Number one reason why it's not considered rape is that it's sexual assault.I think there's a pretty big difference between saying "not all succubi are bad" and "my friend who tried to rape you isn't a bad girl" though. Like if I caught one of my friends trying to rape someone I'm in love with (or not it doesn't really make a difference), I would beat the shit out of them, turn them in to the police, and never speak to them again. I certainly wouldn't go "oh they're totally the type to do this actually but they're not a bad person". But I guess this is a classic example of the rapist being a hot woman so it's not really considered rape by anyone involved for some reason.
I also think people can separate "she did something evil" and "she's evil". Both are separate moral judgements.