My perspective on this seems pretty straightforward, but maybe that's on me for not being clear:

If somebody finds the act of self-immolation abhorrent, which is reasonable, that is still not sufficient reason to discount his political motivation. He articulated that clearly and, furthermore, was also pretty clear that he feels implicated by US support for the genocide in Gaza.

I wouldn't require anybody to accept any of those things, though I'm happy to argue that they should since I believe that is the case. Self-immolation has a long history of political protest that has accelerated in popularity since 1963, and has been used in a variety of ways to express despair and helplessness at an impossible political order. Sometimes I agree with the view that's being expressed (this case, the aforementioned incident in 1963, etc.); sometimes I don't (a pair of Israeli settlers did it to protest disengagement from Gaza in the mid-2000s); and sometimes I'm ambivalent (it was borderline common in Eastern Bloc states as protest against the USSR) but it feels both uncharitable and incurious to simply wave the action away as the work of mental illness.

There is a habit that seems common in good liberals where they are skilled at making the right broad affirmation but never seem quite willing to accept the political urgency of the moment. That's obviously their right, but it serves a parallel purpose of disqualifying arguments without dealing with their substance. You can think that Aaron Bushnell is crazy *and* that he's right. Etc. But the way it plays out is that every war is bad, except the current war which is necessary. Every past protest that succeeded was done the right way, but the current one that hasn't succeeded is bad and done the wrong way.

History won't stop coming though, so they'll get it eventually. Fukuyama is wrong every day.