My "favorite" part was watching them kill Overwatch with Overwatch League. Overwatch was popular because people played it casually. Activision thought it would be great to make it a professional sport. Eventually every balance change was aimed at preventing some pro team from complaining and they made the game completely unfun for casual players. So they all stopped playing. Meanwhile, Overwatch League was massively unprofitable and the privately-owned teams all pulled out after losing everything. Probably the worst business decision in gaming history, or maybe even in Fortune 500 history.
At this point, I'm just waiting for someone else to make games with the quality and "spark" of old Blizzard. It will happen. Probably not at Microsoft, though.