I think this will be just another miscalculation and flop
How likely is such a blunder, however?
In 2000, the Finnish telephone company Sonera formed a group, "Group 3G", along with Spanish Telefonica, basically wasted billions of euros in the auction of German UMTS frequency ranges. There was a lot of hype and a lot of competition, but I do not think any of the officers in charge got any backlash (quite the opposite, golden parachutes, eventually), probably because the majority of their stocks were government-owned.
Is it possible that this is a billion-dollar blunder by MS officers? Could it be they simply do not understand open source licensing and software development at all, and have mistakenly applied the traditional "one who has it and keeps it secret, owns it" approach to GitHub? Nah, I don't buy it.
Having thought about this off and on for a couple of days after deleting my GitHub account, I think the most likely explanation is that MS sees this as buying goodwill among the free/open source ecosystem. Could it be they have problems in hiring the best developers, especially those already working on open source projects? For example,
mono is still treated as at least slightly suspicious by many developers and even some users, so much so that mono-based packages in e.g. Ubuntu often do not mention it in their short descriptions at all. (Mono-related packages use the "-cil" suffix; whether this is intentional in obfuscating the relationship to Mono or not, I do not know.)
The risks to GitHub users still remains, even in that (innocuous-seeming) case. If we extrapolate from history, this effort will not provide the results MS hopes for, and at some point, that means a fundamental change the users do not like.
Like what happened to
Netmeeting. It is interesting to note that MS removed it from Windows XP before there were any alternatives; even Skype was launched several years after that. Most likely reason for the removal was that they couldn't get any revenue off it, but maintenance costs were pretty high (video codecs, webcam support). They did, IIRC, try to bundle it with Office at some point, probably in an effort to try and extract at least some revenue off it, by getting users who don't really need Office but wanted Netmeeting, to buy the Office package. This was around 2000, so very much during the Office wars.