My pet peeve, as you call it, is with people who decide to write in another individual's original universe without respecting the in-universe rules that individual created or, if they change the rules, without doing so in a way that enhances the story.
Clear enough? You were operating under misinformation, which I corrected. You perceived that as an "attack" on a fellow author, who is more than capable of standing up for himself. Then you attacked me.
As for "derailing the thread" - you're not a moderator here, and kindly refrain from dictating to me which facets of crossovers and writing in somebody else's universe I choose to discuss.