It wasn't a good move but I can still see and understand Cuban's reasoning.
Before 2011, Chandler was an incredibly injury prone center who couldn't even start for the Bobcats. He was terrific in Dallas, but even then he was such a fouling machine that he'd have to sit for long stretches, and the last five minutes of every Mavs game was a stressful event since Tyson was almost always playing with five fouls.
At the time NOBODY could say definitively that he'd continue to play as well as he did in 2011 or that he'd stay as healthy as he has. You're a ing liar if you say otherwise.
At that point Dwight Howard was also playing at an MVP level and, even with a healthy Chandler, would have been a massive upgrade. If you say you knew Dwight Howard would, in less than two years, devolve into an injury prone pussy, you're also a ing liar.
You can LOL at Cuban for signing tier centers to better deals, you can LOL Cuban for what, in hindsight, was absolutely a horrific decision. But you cannot seriously take him to task for thinking in 2011 "I have no idea if Tyson Chandler can stay this healthy again, nor do I have any clue if he can keep playing at this level. I also see a guy in Dwight Howard who at this moment is a significant upgrade and possibly available soon".
Yes, Cuban made a huge mistake, but don't act like he has ing Bill Russell in his prime and dumped him for a shot at Tree Rollins.