I'm pretty sure that when I defend the right of, say, OWS to protest, I'm not defending whatever it is they're protesting.
They went for a breezy tone and forgot to pass it through Legal. I doubt they're sexists. I'm sure sexism would, in this day and age, hurt them more than anyone else.
That's not really the case in the software industry. There really are very few women in the field. That's why we need to call out stuff like this — so that female programmers' lack of visibility doesn't become an excuse to marginalize them.
I don't think it was intentional on the job poster's part, but the fact that he didn't catch how it sounded of proofreading definitely indicates a blind spot to sexism.
They went for a breezy tone and forgot to pass it through Legal. I doubt they're sexists. I'm sure sexism would, in this day and age, hurt them more than anyone else.