I noticed this as well. I wonder how much of his assertive and dominant character also influenced empire-building politics. Management is responsible for setting the general tone and language for the corporate culture.
Even though "we" and "our" sounds better in principle and rightfully gives credit to the team/company as a whole, I've noticed that management oddly like people that speak the opposite way. Speaking about things as "my" team, what "I" would like to do, or what "my" idea is. Saw it recently, even. Coming from a (mediocre) junior developer, coupled with a cocky attitude, and it absolutely infuriates me to watch it.