If a woman publicly asserts that she wants to "get" an "attractive man", would you also think that she is being alienating?

Sure. I usually wouldn't care enough to object, but it would seem faintly wrong in a way that 'I want to have sex with an attractive guy,' or a concrete statement of any other desire, would not.

And I most certainly would not expect most heterosexual guys to participate in a web-community that often talked about how to "get an attractive man".

in my experience, only men are accused of being alienating or superficial...when they are honest about their desires.

If you really meant that, then your experience seems weirdly limited. Or are we just talking about sexual desires? I think the statement still fails in that case, but not as soundly.