Re: So ?
I don't know if I've been in IT for longer than you, but I've been in IT for longer than Bill Gates.
No software runs exclusively on Windows. Alan Turing wrote proof of that. The only issue is whether the cost of migration between runtime platforms is greater than the cost of staying.
Microsoft became a profitable company by ensuring that people perceived that cost not to be worthwhile. It increasingly seems to be the case that they want to prove the opposite.
I don't predict a rosy future for them.