I wonder if it’s even that complicated.  I have only played a couple PbTA games and never burning wheel.  But in my limited experience I’ve always felt that in PbTA I was never really playing my character, in the traditional sense.

Most of the time I felt more like I was shaping the game around my character.  Sure part of that was acting in character through dialogue but that only felt like maybe half the time.  My character, all the characters really in that system feel like water and I was shaping the path they followed and not the water itself

Maybe he just wants to get back to the more standard flow of being more of a player level view of the story and not actually shaping the events around him.