Here is something that Bass might be doing to hurt the team albeit not his fault.
He is hurting the trade value of Sully. If sully is a key (along with bradley and draft picks) for ainge to do a serious upgrade trade then we have a problem. Bass given minutes is playing as well as sully or better. Sure sully just had a good game stats wise against golden state but night in and night out bass brings it. Yes many playoff teams would love his services off the bench but I'm sure they are going to get him for not a lot (see green, rondo). AND if bass can only garner…what a second rounder? What does that do to sully's value?
It does nothing to Sully's value. Bass' value may describe where Sully's value is, but that's it. His playing well does not diminish another player's value. Sully's value will also be somewhat higher since he's under more team control -- next year he's scheduled to make a third of what Bass makes this year, and after that he's a restricted free agent, which gives teams an opportunity not to overpay to keep him. Combine that with the fact that Sully is younger and his game is likely to continue to improve, whereas Bass' game will not, and we're starting to talk about apples and oranges. Even if you believe that Bass and Sully have similar value at present when it comes to on-court worth, contract situations and the potential for future growth give Sully a lot more value on the trade market.
Finally, Ainge is signalling to the league that he thinks Bass is worth more than a second-rounder, and seems willing at present to keep him on the roster through the end of the year if better offers don't materialize, much as he did with Humphries last summer. Ainge has generally done a very good job of maximizing his players' worth in trades, and if traded, Sully (or Bass) will command a decent return.