The fact is that there are a lot people who do think "women/men want" when they hear someone saying "women/men want", and don't understand that these aren't just statistical trends.

I would tend to be one of them. But no woman or man is a 'women'/'men'. What the group -- as a second-order simulacrum -- wants isn't necessarily what an individual instantiation of the group wants.

Also, I do feel like there are tendencies towards such over-generalization even among active LW commenters.

Given that all I have to work with is your quoting him as saying "a certain behavior" is suboptimal (in a manner so vague I haven't a clue what position either of you were staking out) -- I cannot begin to make any informed statements on that topic.

Just to play devil's-advocate here -- have you considered the possibility that your feeling here represents an over-generalization about LW'ers over-generalizing?