I still think there was more to the story with Semih. I certainly understand giving him away for this season, because with his injury (he only played in 4 games after being traded), and his inexperience, he just was not someone they could count on in the playoffs. However, in theory, he should have had value going forward as a young center.
I have heard rumors that there were real concerns about his work ethic, dedication, and his interest in staying in the US instead of returning to Europe.
I also think it may not have been a coincidence that just a couple days before being traded, he returned home from visiting his sick relative (which the team gave him extra time for over the All Star Break), and he looked absolutely horrible. He looked like he was completely out of shape (which is shocking after just a week or so off), and his head was not in it.