Some of the opinions here are uninformed and it appears they haven't really been watching the games.
For starters, the title of this thread is ridiculous!!
Here is my opinion, take it or leave it: BBD is 24 yrs old, in his 2nd year(before then was a rookie) and improving every season. Because he is on a major championship team with the likes of the 'Big Three' and Rajon Rhondo, he doesn't get the looks he might get elsewhere and yet, there are times he does get those looks and he proves how good he really is. Some here complain how he only got 16 pts/game in the 09 season starting in place of KG when KG was out injured. That year was his first year as a non-rookie and he was, what?, 22 yrs. old and 'starting' in the playoffs, in place of KG, no less!!!. Well, I think his 16-plus points were pretty good in the circumstances. Since then, his amazing defensive talent, rebounding and working on and improving those areas where he needed more practice, such as his jump shooting and figuring out how to move better so he wouldn't get his shots blocked in the paint have been consistently more successful. This shows me he's not only willing and able to work and get better every year, but also, that given playing time as a starter, he will become one of the best NBA players around. He is unique. It is highly unusual for a guy his length to play the position he does and yet he moves so fast and his size is so daunting that he actually plays PF very well. He is still new and young and the refs don't give him much lee-way, such as not calling foul on the opposing team when his legal screen near the line in the paint is bashed illegally (and wow that must hurt).
And now here is my prediction: If KG doesn't retire after next year when his contract is up and Baby is still his second, I believe Baby will have to go to a different team to achieve his career goals. He needs to play the starter position. Many here like to call him a role player and well, that is what he is right now, but that's due to the circumstances I just pointed out. BBD is young, just starting out, has exceeded expectations of many and I believe he will continue to do so, when given the chance, and he will be given the chance. It would be unwise of him to waste his talent and career. I know that Tony Allen seems to feel the same way and he has finally left the Celtics. I hope that his talent will carry him to a starter position also.