you cant livein hindsight but you absolutely grade moves in hingsight
This is true.
However, using hindsight to grade how things actually turned out and using it to say that a team should have known better at the time and made a different choice are not the same thing.
You tend to do the latter much more than the former.
Teams can only go with the info they have at the time and hope they are right.
Case in point:
When the Lakers did the Dwight/Nash deal...nearly every "expert" said the Lakers were back and expected a Lakers/Heat finals.
Yet, when it blew up, you (and some of those same "experts") were acting like the Lakers should have known what would have happened and not made the trade.
When the Knicks took Porzingis, Knicks fans booed, "experts" said that Phil lost his mind and mocked the Knicks. The fact that he turned out to be far better than anyone thought, doesn't mean that the teams who didn't take him made a mistake.
It's just good on him that he turned out to be better than expected.
Where hindsight CAN be used as a legit criticism is when a team takes a flyer and it blows up on them.