From my understanding (not part of the SF tech bubble), S.A. had his shot as the CEO of a company that came to prominence because of a GREAT product (and surely not design, manufacturing or marketing). Just consider WHEN MS invested in OpenAI. He probably went too far for reasons only a few know, but still valid ones to fire him...
His previous endeavor was YC partner, right? So a rich VC turning to a CEO. To make even more money. How original. If any prominent figure was to be credited here beyond Ilya S., well that would probably be Musk. Not S.A. who as a YC partner/whatever played Russian roulette with other rich folks' money all these years... As for MS hiring S.A., they are just doing the smart thing: if S.A. is indeed that awesome and everyone misses the "charisma", he'll pioneer AI and even become the next MS CEO... Or Satya Nadela will have his own "Windows Phone" moment with SamAI ;)