I don’t care how many yachts Gaben owns, he’s free to do whatever he wishes as long as he provides me a great service that I’m willing to use money towards.
And Microsoft did try really hard back in the day to make Linux go away. Luckily OSS community was already large enough that they were able to fight the legal cases and the whole thing didn’t dry up. Nowadays Microsoft endorses Linux because they decided they can squeeze value out of other people’s free work for themselves (and because pretty much the entire server industry runs on Linux anyways).