I can't help myself from questioning the example provided.
Friend #1 asked out his love interest and she said yes. It turns out, however, that another one of his friends had gone on a few dates with her and assumed they would be going to prom together! Friend #1 knew about the dates but assumed this wasn’t a big deal. To friend #2, this was a very big deal.
Like, Friend #1 is just a bad friend?
Friend #1's mistake wasn't asking someone out; ...
Yes, it was?
...it was not recognizing that friend #2 had built (arguably unreasonable) expectations around an ongoing courtship.
It was not recognising that Friend #2 had built a completely reasonable expectation that his friend, who a) is aware of the dates b) is his friend, won't interfere in that?
Maybe we just have an object-level disagreement about dating culture, though.
The most probable intuition behind the disagreements, it appears to me, is that "a person going around doing a bunch of good things and a little bit of bad-evil things is net-positive and we should keep him around even if we can't fix him, and a different person doing the same amount of evil things but not 'offsetting' them with anything is a bigger problem."
Your point could be made even stronger by including people for whom it's even harder to feel compassion, i.e., someone who is deliberately cruel, rather than just someone who is dumb and isn't trying to fix that. However, even then, I don't think your "disgust" is entirely fair.
If we accept certain uncontroversial assumptions from cognitive science and biology, do we not come to conclusions, that for every person on Earth, if you were born with their genes, into their environment, you would be them?
I'm not trying to start a free-will debate, but this seems to me trivially true.
That's where kindness can come from. You don't have to excuse anyone's actions/stupidity/failures in their responsibilities, but instead of feeling "disgust", you could think of ways to help them from where they stand, or just let them be.
Some of these are good, not all of them