It’s not crazy per se, but I think it’s a negative gain overall. I love Gwen, but I’ll also be the first to tell you that there wasn’t really much to her–the most memorable thing that she did was to die. And so bringing her back just makes her another blonde girl in Spider-Man’s cast, while taking away the one thing for which she’s best remembered, the fact that she was the girl that Spider-Man failed to save, the one that died because he was Spider-Man. Losing that is no small thing, and it’s not worth getting back a character that’s so relatively thin. Better, if you want to go that route, to introduce a new girl, and make her more interesting than Gwen.