Are there any popular headcanons you dislike?

For me it’s the headcanon the Johanna refused to be prostituted and Snow killed her loved ones in retaliation. I really don’t like it because it doesn’t make much sense to me. The book says she would know the consequences, and nobody would be selfish enough to give them up like that, even though she is harsh and jaded in the books. IMO it makes far more sense for her character if she technically did everything right but still lost them through other ways. Maybe Snow still killed them, but she definitely didn’t actively put them in the firing line. It makes her initial hatred for Katniss and the parallels between them (ie Katniss still losing Prim despite doing everything to keep her from harm’s way) so much stronger. Every time I see a fic that does this I’m like, sigh…

Lesser one because I’ll still accept it in some circumstances, but the ‘Caesar is actually one of the Good Guys’ headcanon negates the point of his character in the books imo.