Honestly, he's a really good 5th big man to have on your roster. His pick-and-roll defense is above average, and his size makes things hard around the rim. That's a legit NBA skill to bring in off the bench.
His problem has always been that he was a theoretical stretch 5 that couldn't shoot well, and he doesn't really bring that much more to the table offensively.
I'd love to have Thomas Bryant in that position (and we still make get him), but Kornet is solid.