He's had a couple down seasons in a row which is a bad sign. Last season he got BBQ'd in a defense he knows well under Fangio and benched. If he'd been in a new defense then maybe I'd overlook that but over the past two seasons he suffered a drop in his play with the Bears, got cut, then signed for a one year with a defense he knows and it was ugly. He had a 126+ passer rating against which is what it would look like if a random fan played corner for us.
Bears saw his skills declining and cut bait at the right time, it seems to me. But all that aside I'd be fine bringing him in on a bargain deal. That way if he can't win a job you cut him. No real risk in that.