I've posted the same thing several times here, and I agree that Ainge is irritating GMs to the point they go out of their way not to deal with him. I'd be surprised if every GM in the league is going to refuse to deal with him at this point, though.
I believe DA overvalues his assets to the point nobody wants to pay his price, but that doesn't mean we have leverage. There are multiple options here for the Celtics. It would be smarter for DA to sell Smart or Bradley cheap, since he isn't going to get much for them anyway. I just don't see, out of all the options they have, why they have to sell cheap on their best asset of the 3.