I'm in complete agreement with you.
I was one of the fans banging the drum for a Peterson trade two years ago (or whenever it was), but that ship has sailed, or in the Vikings' case, sunk. They could have unloaded him and that ridiculous contract and actually gotten something in return. Now, they're simply forced to release him and get nothing.
But he's got no place in Dallas at this point. In fact, based on what he looked like when he did play in 2016, he's in for a rude awakening when it comes to available jobs and teams willing to pay him anything close to what he thinks he's worth.
Adrian Peterson is at a true crossroads in his career.