Maybe. Beyond the expense of living in New York City, he has like five other power forwards to compete against. He'll have no visibility whatsoever, as the Knicks may be the worst team of all time, and he's perceived as both having broken his word to the Spurs and not wanting to compete. Also, he turned down a better offer from the Clippers, so no one knows what he wants. Plus, the second year from the Spurs could be seen as an insurance of $10 million in case he got hurt. Passing on all this for five million more doesn't seem the wisest.