This article, like many others, seems to overestimate how large the actual numbers of developers is at Microsoft, as opposed to full teams with Test and mgmt and their associated marketing, sales, etc. organizations.

The .NET GC was roughly 1 person (sometimes a little less, sometimes a little more). Most of the base class libraries were one person. Even larger things, like the text editor, were usually a senior person and one or two very junior ones. And this is software that has to run on a not-at-all-fixed set of hardware platforms :-)

In my time there, I never saw or heard anyone "think they can solve problems by throwing lots of people at them." Uniformly, the decisions made to get things shipped were to either cut the features that were the combination of the furthest behind and least value to the market or to pull over extremely senior talent that had already gotten their parts shipped.

Of course, it was a big company, so YMMV. Can't speak for much more than dev tools, office, and windows.