I agree that that the odds of any Boogie deal this year with any team are low.
However, big time superstars have been traded in this league and sometimes trade themselves (via FA). So a deal is not impossible this year before the deadline.
For Ainge it comes down to his tolerance for risk vs. payback. He seems fairly risk-averse but he has taken calculated risks in the past and sometimes has lost. Thinking about how he brought back Antoine Walker, for example, not that his issues were the same, they definitely were not, but the point is about risk tolerance for a given payback, not the specific risks by themselves. Read carefully the quotes by walker834 of Ainge. He is not saying he would not trade for Boogie, in fact, he actually states that for the right deal, he would consider it, in spite of his baggage.