Oh yes, good tsar, bad boyars.
Whenever Microsoft does something good, like open-sourcing some dev tool, it's because of Nadella. But he isn't responsible for the state of Windows. If only someone told him about the forced telemetry, forced updates, forced Microsoft account login, pushing Edge down users' throats, and so on... I'm sure he would fix all those problems, but sadly, he doesn't know. And it's just a coincidence that all this stuff intensified when he became the CEO.
I even saw a comment on HN saying that it's "Ballmer loyalists" who are truly at fault for the current state of Windows.