Strictly speaking, the "disdain" for a woman who can't find a partner is part of the culture to the point that we've essentially normalized it and don't see it as an issue. Otherwise why would one of the first questions to a working woman usually be "So when are you going to have kids?", implying that a woman's only worth is in her ability to perpetuate the species. As a single, working woman myself, I've been asked that question any number of times, despite indicating that I am currently happily single and am approaching the age when child-bearing becomes dangerous for my health. It's becoming less of an issue as women's rights become more normalized in the culture, but it's still a problem. I would be willing to bet every single woman I work with who is not in a committed relationship gets asked about it at least once a year by male coworkers.
I still am a nerd, and happily so, thank you, despite it being cooler now to be one, but I can recall when I was still in middle and high school when I was derided for my intellect; I was lucky in that I was able to come to the realization that having a few good friends and doing well in school was more rewarding for me than being popular or involved in the more stereotypical activities for my gender (didn't become a cheerleader or homecoming queen because I didn't want to bother, for instance). So yes, I can imagine being able to speak up against those individuals who were lumped into the same group I was but were doing things I didn't agree with. I'm probably the exception to the rule, however; that I will grant you. Regardless, I don't see why this prevents them from speaking out. As I said to JoeMorgue, you may not bear responsibility for what others say or do, but you can't argue that you DO bear responsibility for what YOU say or do, so if you are associated wtih the toxic elements of your grouping because you didn't speak up, you really only have yourself to blame.