MS has changed from proprietary software vendor to a spy-on-the-users-and-try-to-monetise-them services company that's trying to be Google. I don't think that's much of an improvement.

Their code used to be their core value and source of profit; they are open-sourcing a lot of it now because that's not true anymore and they might as well get some publicity out of it. If you look at companies like Google and Facebook who publish lots of open-source, you'll see the same trend --- it's opened because it's not worth anything to keep it secret anymore.