Jordan's a good offensive player. Rolling to the rim, catching/finishing, and getting putbacks might seem like relying on athleticism or on teammates, but they're skills. Not all bigs can do those things and very few can do them even close to his level. I know he had CP3 on his team, but you could've said that about Tyson Chandler in New Orleans, and he's maintained a high FG% ever since. Dallas was able to set up him and Brandan Wright for shots at the rim, so why couldn't they do it with DJ?
If he expects to be the focal point of the offense, especially if it's through the post, that could be a problem, and yeah he's been a bit overrated on defense, even before Doc's DPOY lobbying. But he's a 26 year old player who does really important things on both ends of the floor, the Clippers did way better with him on the court than off (even when you factor in CP3 and Blake), and he hasn't missed a game in four years. This is a good signing.