While Nate is a great athlete, he's not a great or consistent basketball player yet. As others mentioned, Nate had games where he dropped 40 points for us, but then had games where he'd be way off, try to do too much, be a distraction. On average with the Knicks 1 in 4 games were great efforts like you saw against Miami. The other 3 were stinkers and he hurt this team more then helped. Perhaps with Curry hurting Nate can step up for that team and be a consistent guy. But as a Knicks fan, I can't see bringing him in here over anyone aside from maybe Lin being a good call.
Toney D will be better when he can get back to his natural role of bench guy. Fields will also be better when he is overachieving energy guy coming in for Melo at SF. Shumpert is miles ahead in terms of ability and maturity and is on par in athleticism.
Also, every time nate goes off like this his asking price goes up. I'm not willing to pay through the nose for what is a bench role player that gives you good games 25% of the time.
Personally I like Nate and i would have liked to see him succeed with our team, but it wasn;t working out and we needed to make room for guys like shump, b.diddy, amar'e, melo and tyson chandler. Nate is not on the same level as those players.