My favorite manifestation of this is people who hate Hayden Christensen but will cut Miss Portman infinite slack. Guys! She was even worse than he was and she ruined half again as much of your childhood!
She made me root for them to cut off Anne Boleyn's head. I don't even remember the point of her character in V for Vendetta, but Guy Fawkes was a traitor and that movie was awful. She was no more or less infuriating than anyone else in Garden State, but since that was compounded entirely of self-satisfied nerd tropes of a particularly irritating kind, that's not saying much. She was actually the most hateful person in Closer, which is saying a lot.
So you're saying it's not her fault she's only in annoying films, and she's a good actress.
Is she? Is she really? I'm not sure she is. She's just pretty. Which is nice and all, but does not justify the posturing or the adoration. Lots of people are attractive. But Orlando Bloom can't get work any more, and Mr. Christensen's résumé isn't growing impressively, so why, oh why, is Natalie Portman so universally beloved?
PS Also, as a friend points out, she has weird alien ears.