This is very deliberate, and a strategy used in a lot of companies and even governments.
Pin all the blame on one person as a precaution. That way when it goes bad it's very easy to use them as a scapegoat, get rid of them, and pretend you've turned a new leaf.
Bonus points if you throw out a couple of new projects which totally show how different you are, but are at the end of the day are nothing more than empty PR moves.
Whoa! There is no place for logic on these boards! You seem like an adult who pays attention. Who sent you!?
But seriously, it's clear people who have been exposed to corporations and pay attention vs those who want a black and white answer that just doesn't exist.
As far as Ballmer vs Nadella, as someone who has been at the company during both of their tenures;
Nadella has a very different style that makes him much more approachable. He's doing much more to try to change the overall company culture and is a huge proponent of accessibility given he has a child who is disabled. So things like the new Xbox controller get green lit under him.
His notable goals are to transform the company for the future, some of which Ballmer had already started. Windows being deprioritized and Cloud and AI being pushed is a cornerstone of that strategy. He also has grown MS focus and contribution to open source.
Does he care about games?
He does see the potential impact on business but he's also an old school MS guy who never worked on the gaming side.
Gaming at MS has largely been about marketing a cool hip brand for Microsoft. From time to time gaming will get boosts of financial support which stop and then they are told to deliver on skeletal budgets. So it will be interesting to watch per usual.
PC gaming is way down the list of priorities and that's just a culture thing. Not saying it can't change but they would need to bring in new blood. They have in the past but it didn't last long as the focus shifted before that person could even get going.