A fan who enjoys the series. I'm not going to pretend it's perfect, but I still enjoy it regardless.
If they dislike the series, I have no problem with that. But when they pretend those who do enjoy it have some sort of mental problem, then they're just being simple gatekeepers.
If they can't accept that certain fans just like*LIKE* the series without adding some negative psychological aspects to it, then by that point they're just being selfish.