From the memo:
> I’m simply stating that the distribution of preferences and abilities of men and women differ in part due to biological causes and that these differences may explain why we don’t see equal representation of women in tech and leadership.
Minus a bit of softening language ("in part", "may"), proposing that women are on average less biologically capable of programming is exactly what he's saying.
Also, because I know how HN works, let me pre-empt the inevitable reply to this one: "but what if there ARE sex differences?! shouldn't we be allowed to talk about that!? Freedom of speech!?!"
Scientists who study this stuff (including those cited by Damore) can and do talk about it, and the consensus is that biological sex differences are not that big of an effect, certainly not enough to explain the gender disparity in tech. What effects there may be are absolutely dominated by sociological factors.
Sociological factors that some companies are attempting to counter, which is what Damore didn't like, which is why he issued his complain-y memo to start with.
And THAT is why people are upset with him. Not because he's an amateur biologist with a day job as a programmer who just earnestly wants to have an innocent conversation about sexual dimorphism. It's because he's just another brogrammer whose jimmies got rustled by the thought of women being his peers, and decided to insult (on average) his female colleagues and create a hostile work environment for which he was (quite correctly) fired.