Here's a pattern that shows up again and again in discourse:
A: This thing that's happening is bad.
B: Are you saying I'm a bad person for participating in this? How mean of you! I'm not a bad person, I've done X, Y, and Z!
It isn't always this explicit; I'll discuss more concrete instances in order to clarify. The important thing to realize is that A is pointing at a concrete problem (and likely one that is concretely affecting them), and B is changing the subject to be about B's own self-consciousness. Self-consciousness wants to make everything about itself; when some topic is being discussed that has implications related to people's self-images, the conversation frequently gets redirected to be about these self-images, rather than the concrete issue. Thus, problems don't get discussed or solved; everything is redirected to being about maintaining people's self-images.
A tone argument criticizes an argument not for being incorrect, but for having the wrong tone. Common phrases used in tone arguments are: "More people would listen to you if...", "you should try being more polite", etc.
It's clear why tone arguments are epistemically invalid. If someone says X, then X's truth value is independent of their tone, so talking about their tone is changing the subject. (Now, if someone is saying X in a way that breaks epistemic discourse norms, then defending such norms is epistemically sensible; however, tone arguments aren't about epistemic norms, they're about people's feelings).
Tone arguments are about people protecting their self-images when they or a group they are part of (or a person/group they sympathize with) is criticized. When a tone argument is made, the conversation is no longer about the original topic, it's about how talking about the topic in certain ways makes people feel ashamed/guilty. Tone arguments are a key way self-consciousness makes everything about itself.
Tone arguments are practically always in bad faith. They aren't made by people trying to help an idea be transmitted to and internalized by more others. They're made by people who want their self-images to be protected. Protecting one's self-image from the truth, by re-directing attention away from the epistemic object level, is acting in bad faith.
Self-consciousness in social justice
A documented phenomenon in social justice is "white women's tears". Here's a case study (emphasis mine):
A group of student affairs professionals were in a meeting to discuss retention and wellness issues pertaining to a specific racial community on our campus. As the dialogue progressed, Anita, a woman of color, raised a concern about the lack of support and commitment to this community from Office X (including lack of measurable diversity training, representation of the community in question within the staff of Office X, etc.), which caused Susan from Office X, a White woman, to feel uncomfortable. Although Anita reassured Susan that her comments were not directed at her personally, Susan began to cry while responding that she "felt attacked". Susan further added that: she donated her time and efforts to this community, and even served on a local non-profit organization board that worked with this community; she understood discrimination because her family had people of different backgrounds and her closest friends were members of this community; she was committed to diversity as she did diversity training within her office; and the office did not have enough funding for this community's needs at that time.
Upon seeing this reaction, Anita was confused because although her tone of voice had been firm, she was not angry. From Anita's perspective, the group had come together to address how the student community's needs could be met, which partially meant pointing out current gaps where increased services were necessary. Anita was very clear that she was critiquing Susan's office and not Susan, as Susan could not possibly be solely responsible for the decisions of her office.
The conversation of the group shifted at the point when Susan started to cry. From that moment, the group did not discuss the actual issue of the student community. Rather, they spent the duration of the meeting consoling Susan, reassuring her that she was not at fault. Susan calmed down, and publicly thanked Anita for her willingness to be direct, and complimented her passion. Later that day, Anita was reprimanded for her 'angry tone,' as she discovered that Susan complained about her "behavior" to both her own supervisor as well as Anita's supervisor. Anita was left confused by the mixed messages she received with Susan's compliment, and Susan's subsequent complaint regarding her.
The key relevance of this case study is that, while the conversation was originally about the issue of student community needs, it became about Susan's self-image. Susan made everything about her own self-image, ensuring that the actual concrete issue (that her office was not supporting the racial community) was not discussed or solved.
Shooting the messenger
In addition to crying, Susan also shot the messenger, by complaining about Anita to both her and Anita's supervisors. This makes sense as ego-protective behavior: if she wants to maintain a certain self-image, she wants to discourage being presented with information that challenges it, and also wants to "one-up" the person who challenged her self-image, by harming that person's image (so Anita does not end up looking better than Susan does).
Shooting the messenger is an ancient tactic, deployed especially by powerful people to silence providers of information that challenges their self-image. Shooting the messenger is asking to be lied to, using force. Obviously, if the powerful person actually wants information, this tactic is counterproductive, hence the standard advice to not shoot the messenger.
Self-consciousness as privilege defense
It's notable that, in the cases discussed so far, self-consciousness is more often a behavior of the privileged and powerful, rather than the disprivileged and powerless. This, of course, isn't a hard-and-fast rule, but there certainly seems to be a relation. Why is that?
Part of this is that the less-privileged often can't get away with redirecting conversations by making everything about their self-image. People's sympathies are more often with the privileged.
Another aspect is that privilege is largely about being rewarded for one's identity, rather than one's works. If you have no privilege, you have to actually do something concretely effective to be rewarded, like cleaning. Whereas, privileged people, almost by definition, get rewarded "for no reason" other than their identity.
Maintenance of a self-image makes less sense as an individual behavior than as a collective behavior. The phenomenon of bullshit jobs implies that much of the "economy" is performative, rather than about value-creation. While almost everyone can pretend to work, some people are better at it than others. The best people at such pretending are those who look the part, and who maintain the act. That is: privileged people who maintain their self-images, and who tie their self-images to their collective, as Susan did. (And, to the extent that e.g. school "prepares people for real workplaces", it trains such behavior.)
Redirection away from the object level isn't merely about defending self-image; it has the effect of causing issues not to be discussed, and problems not to be solved. Such effects maintain the local power system. And so, power systems encourage people to tie their self-images with the power system, resulting in self-consciousness acting as a defense of the power system.
Note that, while less-privileged people do often respond negatively to criticism from more-privileged people, such responses are more likely to be based in fear/anger rather than guilt/shame.
Stop trying to be a good person
At the root of this issue is the desire to maintain a narrative of being a "good person". Susan responded to the criticism of her office by listing out reasons why she was a "good person" who was against racial discrimination.
While Anita wasn't actually accusing Susan of racist behavior, it is, empirically, likely that some of Susan's behavior is racist, as implicit racism is pervasive (and, indeed, Susan silenced a woman of color speaking on race). Susan's implicit belief is that there is such a thing as "not being racist", and that one gets there by passing some threshold of being nice to marginalized racial groups. But, since racism is a structural issue, it's quite hard to actually stop participating in racism, without going and living in the woods somewhere. In societies with structural racism, ethical behavior requires skillfully and consciously reducing harm given the fact that one is a participant in racism, rather than washing one's hands of the problem.
What if it isn't actually possible to be "not racist" or otherwise "a good person", at least on short timescales? What if almost every person's behavior is morally depraved a lot of the time (according to their standards of what behavior makes someone a "good person")? What if there are bad things that are your fault? What would be the right thing to do, then?
Calvinism has a theological doctrine of total depravity, according to which every person is utterly unable to stop committing evil, to obey God, or to accept salvation when it is offered. While I am not a Calvinist, I appreciate this teaching, because quite a lot of human behavior is simultaneously unethical and hard to stop, and because accepting this can get people to stop chasing the ideal of being a "good person".
If you accept that you are irredeemably evil (with respect to your current idea of a good person), then there is no use in feeling self-conscious or in blocking information coming to you that implies your behavior is harmful. The only thing left to do is to steer in the right direction: make things around you better instead of worse, based on your intrinsically motivating discernment of what is better/worse. Don't try to be a good person, just try to make nicer things happen. And get more foresight, perspective, and cooperation as you go, so you can participate in steering bigger things on longer timescales using more information.
Paradoxically, in accepting that one is irredeemably evil, one can start accepting information and steering in the right direction, thus developing merit, and becoming a better person, though still not "good" in the original sense. (This, I know from personal experience)