Are you certain that memo was making an argument that "women lack innate aptitude compared to men"? It's been a while since I read it, but it seemed to me that it was arguing that differences in gender representation may be mostly attributable to differences in the degree to which men and women were attracted to high-pressure jobs at Google, rather than because of discrimination in hiring or promotions, and that the gap would be better addressed by making those jobs intrinsically more attractive to women, rather than by hiring quotas.
That was, well, one weirdo and a bunch of laypeople (who were, one suspects, into the idea for political/ideological reasons), though; I don't think many _programmers_ ever believed this.
https://en.wikipedia.org/wiki/Google%27s_Ideological_Echo_Ch...