Shows the lack of self-criticism of that group perfectly. Many atheists and skeptics take the loudest and most obnoxious of their opponents and declare them the face of the movement, or focus their attacks on that group of people (it's one reason I stopped reading Pharyngula--Dr. Myers does this constantly). When the same thing is done to them, it's all because we're a bunch of sexist pigs. It couldn't POSSIBLY a consistent application of the principles they themselves utilize!
It never fails to amaze me that the loudest opponents of discrimination seem to always be the most guilty. Many people opposing racism express flagrantly racist views and advocate blatantly racist policies. Many feminists are so focused on bashing males that they ignore working for women's rights. Many people working to help those with disabilities focus on their disabilities (by that I mean, for example, I was once told that I could never criticize a guy who was being a complete jerk to me, because the guy was a parapalegic--to which I responded, to paraphrase, that I don't care how many limbs he can use the guy was being a jerk). The Atheism+ croud are so focused on attacking mysogenists that they can't see how sexist they're being.
(I don't mean that EVERYONE working to solve a social issue is guilty of that issue--I know feminists that aren't sexist, for example. I just mean that it's a very real danger, one that far too may people are guilty of and which I have very little symapthy for.)