The memo literally lists the biological/psychological traits of men and women that may have caused the gender gap in tech. (He tries to clarify that he is talking on a population level and not talking about individuals)

He is not talking about raw programming skills, but the tech environment. And then he goes on to point out how the tech environment could change so that more women would want to be a part of it, or to stay in it longer once they were in.

In other words, he was saying there is something in tech culture which is inherently less palatable for the average woman than the average man. He never claimed that the culture was good and the women were deficient. Instead he said the culture should change instead of artificially trying to fill it with equal ratio hires.

Then in a pure meritocracy, why would they not succeed? Ergo the memo itself is a straw man.

Did you read the thing? It was very clearly about statistics. The message of the memo was not "women are biologically unfit for tech," it was, as a biological tendency, women are more likely to have traits which disincline them to have an interest in tech-related things, and therefore end up in tech.

To me this says very obviously that women can and are intellectually superior to men on individual cases. But we would not expect an even 50/50 distribution of tech interest among genders.

Feel free to refute that as a separate claim, but if your take from the memo was "all women are biologically inferior and cannot match or be better than men," then I would say you were not being intellectually honest when reading it.

It doesn't make that argument either. It makes the argument that since less women (will on aggregate) be interested in CS then men, less women will be in CS.

And that less women being interested in CS has _some_ basis in biological differences.

Whether you agree with that or not (the research does support it pretty strongly, but is certainly not settled), it is a reasonable argument.