In fact, if I were Andy's coach, I would never ever tell him that he has achieved most of his dreams or that he has a career dream for about 99% of tennis players out there. I'd rather encourage and motivate him for more. Look at Federer in this instance, now this guy has achieved most things in his career and yet age 32, he goes and gets a new coach. I don't see Federer fans opposing that; in fact, they are quite delighted about it. Some are even predicting 'he's back'. The thing is, Andy himself isn't saying. He isn't saying he lacks motivation or that he's not 100% yet. What he's saying is that he's playing back to his full fitness and level. What I am doing here is simply giving my opinion based on his recent performances and nothing more.
Of course Andy being all satisfied and giving up the racquet at this mid and prime stage of his career will benefit certain players as they will end up winning more in absence of a full competition, but that's never a good for tennis. Because there's only so long you can put up with old faces and tell the younger ones that they have achieved their dreams when there's still so much more to go for.
And not only as a coach, as an Andy fan as well, I would never encourage Andy to think that way.