Because we traded two top 50 prospects for an aging knuckleballer who had just put up a career year. Basically the definition of selling high from the Mets and we took the bait. Not saying that d'Arnaud/Syndergaard will both be studs, but I'm sure a lot of people would have preferred to trade for a Price or Latos (yeah I know) rather than Dickey.
It's all in terms of value, a lot of people advocated trading Bautista for Profar when the latter looked like a surefire stud, and here we are. Prospects are highly volatile.