This is interesting and born out by my experience. And because for many years people assumed my pseudonym represented a male, I have definitive proof that it stems from sexism. When people thought I was a male, the insults had a very different tone. They were always on the intellectual/political playing field, tough and challenging but never personal.Now, when things heat up, crude and nasty misogyny appears, the most common being that I'm a bitter old spinster who needs to get laid --- which would come as something of a surprise to my husband. But in normal times I mostly have to put up with being condescendingly lectured about what a silly old bubblehead I am for ....fill in the blank. (My favorite all time comment has to be the fellow who complained, "You wrote a lot better before you came out as a woman.")
I have spent some sleepless nights worrying over some of the personal comments, many of which have been so deeply insulting that I'm not sure I'll ever be able to forget them. I think people forget they are dealing with a human being --- or simply take pleasure in dehumanizing women. Either way, I've come to see it as yet another glimpse of the hideous underbelly of the species.
I should take this opportunity, however, to thank those commenters who take the time to challenge the personal insults on my behalf. I try not to respond myself because if I do, I end up expending emotional energy that I just can't spare --- and it tends to escalate in ways that scares off the reasonable people who would like to have an interesting conversation. But I very much appreciate those in the community who step up and call foul when things get out of hand and I should say it more often.