IMO Gruden wants the attention, but 10 yrs out of the league, going to bed at night without headaches of coaching and being a talking head. He gets paid handsomely to talk.. If the fire has not been there for 10 yrs how can he get it back? The money will not bring back the fire & desire to put in the time to be a top notch coach. He already has a ring, so that desire is gone. Miami saw it with JJ. Once you are out, by your own choice and you see what its like to be human, its gone. The guy is done, whether he comes back or not.
Joe Gibbs came back for the cash. Very little there.
I live in UT country and have to listen to the Gruden talk up here. Its like watching an episode of Fantasy Island. There are some here who actually believe the man will come to UT. He did not 5 yrs ago, not coming now. Its over for him as a quality coach. I'm not saying he will never coach again. He will come back at the end for a large pay day, because people will not let go that he was a quality coach once.
Gruden is in a position to be picky. The guy has a Super Bowl ring, had a successful spell as the Raiders head coach and is the most successful Buccaneers head coach in their history. So unlike first time head coaches, or retreads that have had to rebuild their reputation (e.g. Ken Whisenhunt), Gruden is still held in high regard and can be picky over any job that is thrown his way without having to worry that he might not get another offer thrown his way.
So it is possible that no team has been able to tempt him out of retirement because the job just hasn't appealed to him. There's no point coming back to the coaching game if the situation isn't right. Another possibility could be that Gruden only wants to coach a certain team (or teams) if he returns and that job hasn't presented itself to date. So perhaps he only wants to comeback and coach the Buccaneers, if so, them offering him the job could actually tempt him back to the sidelines whereas let's say the Chicago Bears offering the job might not.
Personally I think he should stay in the booth because he's been away for a long time and has nothing to prove, but at the same time I could understand him wanting to return for one last job because a return to the booth would always be open to him when that coaching job ends.