because there are more combinations of 234 flops, ldo
anyway, even if we flop two pair we're likely to get action, where if we flop two pair with 72o we're way less likely to get action

also, sometimes an ace will be good enough to win a small limped pot, especially in position
I'm not saying I'm 100% correct, but I'd have to see some statistics or some more convincing arguments than "what are you hoping to flop"