I think your post answers your questioning. It was to take the pressure of Orton, fresh start with no potential of chasing the game immediately (which didn't work out anyway).
Regarding the coaching, it's like I've read here last season and these first 5 games: "Hackett is being too cute". I don't think he's as bad an OC as many would like to lead themselves to believe, I just think he really has no concept of a complete game plan for 4 quarters and changing on the fly/dropping something that has no business being called again and again (Shotgun handoff: CJ up the gut, 1/2 yard gain).
If this coaching staff fails this season I strongly hope that Tom Clements makes a return to Buffalo or they make a push and throw big money at Darrell Bevell.