EDIT: I leaving this for people to see what I said, but I’ve edited it to the way I should have said it. I’m unhappy with myself, because I really should leave the asshat naming to other people who are far better at it than I am.

One thing that strikes me is that, in theory, there are at least two kinds of potential asshats with respect to RPGs at conventions.
Asshat 1: this asshat puts problematic content in their game, subjects people to this content, and has no interest in reflecting at all on the nature of that content or how others might find it disturbing, and will get prickly and defensive when this is brought to their attention.
Asshat 2: this asshat is figuratively a fragile flower, disturbed by even the slightest reference to the most trivial thing. They are probably intensely political about it too, or at least will have very different politics than you do. The game will not progress because asshat 2 will be complaining all the time.
I think that both of these kinds of asshats exist; I have met both in my life. But here is what I have learned:
* genuine fear of asshat 1 ruining a convention is a fear experienced by reasonable and wonderful non-asshat people in my life, because they have experienced asshat 1 so often and the experiences were miserable and left real marks that linger.
* genuine fear of asshat 2 ruining a convention is almost entirely felt by asshat 1’s. Its a pretty good test for it, I think.

I think there are two fears involved here.

One is the fear that someone will ruin a convention by bringing problematic content into the game, subject people to that content, and have no interested in reflecting at all on the nature of that content, or how others might find it disturbing, and will get prickly and defensive when this is brought to their attention.

The other is the fear that some figurative “fragile flower”, disturbed by event he slightest reference to the most trivial thing that reasonable people would not find disturbing, and who if given the opportunity with a safety tool like the x-card will ruin a convention by x-carding the crap out of everyone.

I think both of these fears can be generated by real experience, in the sense that I have met both of these kinds of people in games. But in my experience, genuine fear of the first situation ruining a convention is felt by many wonderful and reasonable people I know based on actual painful experience that left lingering harm. In my experience, genuine fear of the second situation ruining a convention is felt most strongly by people who are often the first person and is for the most part theoretical.

If you are not the first person, but are genuinely afraid of the 2nd person ruining your convention, I really have to ask why?