I'd like to see him give it another go, but another injury doesn't just end his career. He's worn down enough that he has to think about the effects later in life.
I also don't think he's going to be one of those guys that has a hard time stepping away. Most of the guys who came into the NFL in his situation had their careers end long ago. He had to have been mentally prepared for that even then, and I don't think that goes away.
I've never felt he was particularly engaging, but it's hard to be worse than the other QBs currently doing broadcasting.