Pierce really worked on his game at various points in his career to adjust to what the team wanted - I think the team would do well to get Pierce in the block against smaller wings, get him some ISOs when Rondo is out and use him in the pick and roll whenever there is a good matchup.
I don't see Pierce's best seasons as wasted. He had a couple of playoff runs in the early 2000s. Then he played sublime basketball in 2008 as the best offensive threat (we forget Ray struggled until the finals), facilitator, all around player, and defender of the other teams best player. He also stepped up his game as needed c.f. CLE game 7, DET close out, and the LAL series. Does it stink that the C's under competent ownership didn't build more effectively around him earlier on? Yes. But Pierce had his own maturity issues and again, the C's lucked into him - change anything and we don't get him. (One spot higher we take Dirk, one spot lower he's gone.)