Folding a Really Pretty hand 5/10 6 Max

If you're always betting 1/2 pot then it can become difficult to build a pot when you have a big hand. It's nice to steal pots for cheap amounts but it's also nice to stack opponents.
Opponents may also be willing to look up your 1/2 pot continuation bets more often than a bigger bet.

I think the reason you should bet more on this particular flop is to orchestrate the betting so that if you are raised you can push and not require as much folding equity than if you had pushed flop in actual hand.

You should be wary of stack sizes though. If button and sb had $750 in this hand then a pot bet is not so good because if they raise they are more likely to pot commit themselves with Kx.