When I was posting the hand I was wondering the same thing.

I have the 9 diamonds, 3 2's, and 3 aces. Hitting the ace doesn't win me the hand in most situations. Op is playing this pretty damn strong for such deep stacks. Diamond or a 2 on the river probably isn't going to net me enough on the river to make it profitable. 4 or 3 of diamonds completely screws me too. Villain may not have a set but I'm not maxing my value on a paired board.

I think this is a clear fold to 3bet on flop but a marginal fold on turn.