> Why do women wear low-cut dresses if not to attract male attention (in the majority of cases)?
Yes, Virginia, this is sexist. Holy hell, is it sexist.
You are characterizing a woman's behavior in terms of how it makes you, as a man, feel. There are many reasons that a human might dress a particular way, but by characterizing it as a gender-based, "she wore that to make me do this" kind of transaction you have incorrectly emphasized a single way. This woman wore it for no other reason than to attract male attention? Really? Are you sure? Her decision is entirely based on how it would make a man feel?
I'm a heterosexual man and I wear certain jeans because I like to show off my butt. That's fine. But am I doing it because I want to attract "female attention"? Not exactly. This turns on a subtle point, but it's very important: I wore them for me, not for anyone else. Feeling attractive is not the same as receiving attention. I don't want to be honked at, felt up, leered at, or even commented on. But I do want to look good. Does that make sense?
This situation is only exacerbated when you bring in gender dynamics: men and women are equal, yes, but women are the ones who've been oppressed for centuries and are struggling up the slope to reach equality. What a man says to a woman exists within this context, so simply reversing the roles and pointing out that it's okay HERE but not THERE is not sufficient.
Check out: http://en.wikipedia.org/wiki/Gaze The section about feminism and the male gaze applies here, too.