Re: What. A. Shock.
The thing is, even if Microsoft were a benevolent organization, there's an unavoidable conflict of interest here. Some manager somewhere will decide he (or she, but I'm laying odds on "he" most of the time) doesn't like something on GitHub and will order an underling to get it removed, without having that decision confirmed by anyone higher up.
Corporate cultures aren't monolithic, and don't determine the behavior of every employee at every moment. At its worst, Microsoft still had good people doing good work; at its theoretical best, it still can't be trusted to police GitHub in a fair and proportionate manner. There's simply too much opportunity for a bad actor to intervene unfairly.
I was never a fan of GitHub in the first place (these public central repositories are using git wrong, and I find that irksome), but I certainly wouldn't be interested in using it now for anything I control.