Also there aren't that many tech companies as big as Microsoft, in terms of either market cap or number of employees. Seems pretty easy to have friends at all of them if you were friends with a lot of people in a CS department at college.

Yeah, that's a more plausible reading. Thanks.

But that undermines the original point about big companies even more. Having friends at mostly big companies is not only not enough to generalize about big companies, but it provides no information about whether other companies struggle with these issues too.