True, comic book fans detest change of any sort far more so than fans of most other fiction. This is part of the reason I prefer Manga.
Edit - That said, I feel there are certain things that should remain sacred. Invent new identities rather than shoehorning new characters into existing identities. Don't piggyback a new character off an existing fanbase nine times out of ten it fails plus it is lazy, creatively bankrupt writing. I know it is hard work but at one time all the classic characters were unknown quantities.