They traded 2 picks for Taurean Prince and cap space. Even if you eliminate dealing Crabbe and a first to clear him off the books (which they woulda needed to do), Prince is better than what they could get at 17, and if all you had to do was trade a lotto protected first to move Crabbe, so be it.
The difference between both teams is that the Nets have given people a reason to trust their judgment whereas the Knicks will always be considered a clown show until their lives start paying off (blame Dolan). The Knicks have to restore their credibility to get the benefit of the doubt when making moves like this and that hasn’t happened yet.