I like him, but:
*Coach T and KG did most of the lifting for the title IMO.
*he's a vets coach, rookies get ignored
*he plays whom he breaks camp with, Ainge put together some good deadline deals and Doc made poor use of the vast majority of them - Green and Kristic among them, he also tolerated Rondo's 15 game emotional melt down over losing Perkins.
*he tolerated Rondo cutting Ray out of the picture more and more after '08
*he never controlled Rondo, eventually tired of him and let him practice and run the games his way - that's not coaching, that's giving in.
You have a vet team with egos that need to be soothed? He might be the guy, but to build/nurture a team? Only with very strong assistants to take care of the details.