Mmm, I would consider slash a far different thing from yaoi. A reasonable portion of slash doesn't fetish homosexuality, it fetishizes those two (three, four, whatever) characters having sex. Look at all the kink memes, for instance; clearly sexuality alone is not sufficient.

He's allowed to be angry any time he pleases; goodness knows I get angry over smaller things in fandom. I just don't think it's a worthy cause until it starts affecting the real world.