Probably a combination of both. He was basically saying to the Texans that they weren't good enough for him (or he was better than them) so it's not surprising that they are bitter about it.
But I also dont think that we will see him get better, or even get close to the level where he used to play. This was his last chance to get a bigtime contract, and he came out on top, IMO. But I doubt there is a super bowl in AZ's future because of the signing.