Google would have killed GitHub as it doesn’t earn money. Google isn’t about developers, it’s about getting data and selling ads.
Microsoft needs people to build things on windows, on azure, on their APIs, etc.
Google literally had the GitHub competitor, Google Code, and GitHub was only formed because google neglected Code. Remember how Google would only support mercurial over git?
And of course, Google shut down Code a few years ago.
I have to remind myself while Google hires lots of programmers and does lots of programming, they don’t really need anyone else to program.
Ballmer may have screamed “Developers, developers, developers”, but what he actually meant was “Windows, Office, developers”.
Windows and Office came before everything. The big change Nadella brought to the table was completely eliminating Windows as a primary goal for the company, and reducing Office’s importance as well.