Contrary to what I've seen discussed elsewhere, I don't think it was actually about the pursuit of perfection. Nina was nowhere near perfect, and that was clear from the beginning. Her dancing was forced and unnatural (and honestly, if Aronofsky had wanted a good ballet performance, he would have cast an actual dancer). Her personality is meek and child-like. She has a history of scratching and cutting, and she's bulimic. Neurotic does not equal perfectionist. In fact, the only evidence that she seeks perfection is that she says it -- squeaks it -- when she visits Thomas. The way she lives and behaves does not indicate any understanding of perfection, nor of what it takes to achieve it. Please, she doesn't even have the bruised, callused toes of someone who's spent any time in toe shoes. I can't believe Aronofsky neglected that detail by accident.
This movie is about manipulation, and it casts women in a harsh light to prove that point. Thomas manipulates his dancers to get a certain quality in their performances. This is legitimate, from what I've both seen and heard of directors, but his methods are unseemly. Also, I would think they'd be ineffective, as the aggressive, confrontational sexuality he tries to use on Nina seems only suited to get her defenses up even higher.
Regarding how this movie is unkind to women, it's the female characters who are, with only one exception, toxically manipulative and damaged. The mother has an unhealthy, smothering obsession; Nina is dysfunctionally neurotic; Beth is petty, jealous and self-destructive; that other dancer is just a catty bitch. Only Lily is presented as happy and functional, but she's also cast as the bad influence and the dangerous presence. Hers is the only character that I didn't find utterly annoying, cliche, terrible and overwrought; yet Mila Kunis's is the performance that everyone seems to be trashing.
We've had more than enough movies that show competitive, ambitious women in a negative light; aren't we bored with them yet? This movie is just a more artfully shot Showgirls, as far as I can tell. And not to beat a dead horse, but if you do a comparison of how ambitious women are portrayed in film versus ambitious men, you'll see there is a hugely unfair disparity.
As for the sexuality aspect, I thought that was utter bullshit, practically a red herring. Thomas equates a liberated and passionate dance performance with being sexually wild, as if there were no other ways to be free and open. As for ...Nina's masturbation scenes, I may be naive, or in some bizarre secret way frigid myself, but I can't imagine anyone so uptight and sexually repressed getting all gaspy and moany after like two seconds of touching herself. Seems to me that it would take her a bit longer to loosen up and get into it. Again, manipulative.
One question -- how the hell was Portman even *able* to get pregnant? At least she had some muscle, but still she definitely looked too thin to ovulate. Nasty.