So both of his top offensive coaches (Payton and Kubiak) wanted him as a free agent, as did his new head coach after studying him. I think that speaks volumes about the film he has put out.
Also there is a good chance that it is a statement regarding his opinion of Carr.
Assuming the money was similar, he passed on the opportunity to play for Sam Darnold or Bo Nix. I'm not saying they are good buddies, but if JJ absolutely did not like or respect Carr he would be a Bronco or Seahawk IMO