This was a useful article, and it's nice to know the proper word for it. Let me see if I can add to it slightly.
Maybe a prisoner is on death row, and if they run away they are unlikely to suffer the consequences, since they'll be dead anyway. However, even knowing this, they may still decide to spend their last day on earth nursing bruises, because they value the defiance itself far more than any pain that could be inflicted on them. Perhaps they'd even rather die fighting.
It looks like you don't reflectively endorse actions taken for explicitly semiotic reasons, and lean toward more pure consequentialism. Based only on what you've said, semiotic actions aren't fallacious when they yield outside benefits in the long run, but are fallacious when they don't lead to other good things. (Because you treat semiotic acts as only instrumentally valuable, rather than as terminal values.)
However, it seems likely that some semiotic acts can be good in and of themselves. That is, we reflectively endorse them, rather than just doing them because evolution gave us an impulse to signal which we have a hard time fighting. Semiotic impulse is certainly a human universal, and therefore a part of our current utility function, and it seems plausible that it will survive intact in some form even after more careful examination of our values.
It seems like that sorts of the things we do for explicitly symbolic reasons are more likely to fall into this category than normal subconscious signaling. If we didn't endorse it to some degree, we'd just make sure not to be conscious of doing it, and then keep doing it anyway. To be aware that we're doing it, it can't conflict too much with our positive self-image, or societal values, or anything like that.
Of course, just because we naively support a semiotic act explicitly doesn't mean we still will after closer examination. Maybe we think engagement rings are a touching form of costly signaling at first, but once we understand more about the signaling dynamics at play making us do such things, we decide that conspicuous displays of consumption make society far worse off. You may then decide not to feed Moloch, and try to lessen the keeping up with the Joneses effect.
Personally, I'm rather a fan of the Apollo program, and the idea that long after humanity has killed itself off, the Voyager probe may still survive drifting among the stars, with our last surviving words inscribed in gold.
Acknowledgement: This idea is essentially the same as something mentioned in a podcast where Julia Galef interviews Jason Brennan.
You are in a prison. You don't really know how to fight and you don't have very many allies yet. A prison bully comes up to you and threatens you. You have two options: (1) Stand up to the bully and fight. If you do this, you will get hurt, but you will save face. (2) You can try and run away. You might get hurt less badly, but you will lose face.
What should you do?
From reading accounts of former prisoners and also from watching realistic movies and TV shows, it seems like (1) is the better option. The reason is that the semiotics—or the symbolic meaning—of running away has bad consequences down the road. If you run away, you will be seen as weak, and therefore you will be picked on more often and causing more damage down the road.
This is a case where focusing the semiotics on the action is the right decision, because it is underwritten by future consequences.
But consider now a different situation. Suppose a country, call it Macholand, controls some tiny island far away from its mainland. Macholand has a hard time governing the island and the people on the island don't quite like being ruled by Macholand. Suppose, one fine day, the people of the island declare independence from Macholand. Macholand has two options: (1) Send the military over and put down the rebellion; or (2) Allow the island to take its own course.
From a semiotic standpoint, (1) is probably better. It signals that Macholand is strong and powerful country. But from a consequential standpoint, it is at least plausible (2) is a better option. Macholand saves money and manpower by not having to govern that tiny island; the people on the island are happier by being self-governing; and maybe the international community doesn't really care what Macholand does here.
This is a case where focusing on the semiotics can lead to suboptimal outcomes.
Call this kind of reasoning the semiotic fallacy: Thinking about the semiotics of possible actions without estimating the consequences of the semiotics.
I think the semiotic fallacy is widespread in human reasoning. Here are a few examples:
Two comments are in order: