> Maybe Microsoft became a bad steward?

The argument before Bungie was divested from Microsoft supposedly was that Microsoft was too conservative in their success chasing: they were supposedly only taking pitches for More Halo As We Know It from "The Halo Studio", and that lead to the strife of teams increasingly wanting to do something Not Halo. Part of the struggle too was that Microsoft definitely owned "Halo" and started to want more control of the IP from the top down (the movie attempt, the novels, the RTS game, the MMO attempt, not all of that was controlled by or even presented to Bungie for oversight, despite being "the Halo Studio").

You can see one of the "lessons learned" here in the deal with Activision: Bungie worked very hard to retain all rights to the Destiny IP regardless of what happened with the project. (It's possibly why it may have indeed been Activision severing the relationship early rather than Bungie, because publishers really do not like it when they don't own the IP, and they probably did have pretty high marginal sales quotas to continue feeling publishing was worth it.)

Marathon was amazing too. It was the first game I played where I glimpsed the possibilities of what video games could eventually become. The feeling I experienced being not-quite-alone on that ship is still quite vivid. I loved Halo and tried to - but couldn't - get into Destiny.

Hoping for the best for/from Bungie.

Halo was good, but the released product doesn't compare to the multiplayer open world that Bungie was teasing before the acquisition.