The "pay me" stuff is not just narcissistic greed, it's pinched from other minorities. There's been a big push in the sci-fi/fantasy convention world to make panels more balanced in terms of representation, particularly black, female, and disabled writers. Many of these people got sick to death of being the "token", often stuck alone on an all-male, pale and stale panel, talked over and dismissed, etc. So there's been a real call for people to be paid properly for their time, increase diversity, and break the lazy habit of pointing to e.g. one black woman out of 50 speakers and saying "look how diverse we are!".
Of course trans people need rep too, but it boils my piss that men who've worn a frock for all of five minutes get to talk on panels about Suffragettes and "women in x industry" and the like, shoving actual experts aside in the name of diversity.