Nadella is obviously a very smart and successful business leader. He achieved his goals and transformed Microsoft into a very successful, healthy company. This is why I personally think he isn’t just a bland idiot like for example Steve Ballmer.

However, it’s clear that Nadella’s goals are everything but noble. He doesn’t care about the product, and he really doesn’t care about the customer. He only cares about number go up.

Ballmer doesn't strike me as an idiot and definitely not bland. He's one of the more colorful tech personalities. MS's almost unassailable lead in enterprise could be attributed to him and the pivot to cloud could not have happened without this. But he definitely fumbled hard on mobile (Windows Phone), Surface (IIRC the initial ARM laptop was a major flop and had a close to 1B+ writeoff) and the disaster that was the Nokia acquisition. I'd say he left at the right time, just as it was becoming clear that MS's bets on Windows Phone and hardware in general weren't paying off.

Nadella plays on level easy.

Too many companies are dependent on MS products so it doesn’t matter how bad it gets.

MS rather disables features instead of fixing security issues and now puts AI in everything in a desperate attempt to force the users to use it.