In Vancouver, Dai had to try a quad in LP to win the gold with Plushy finishing ahead of him in SP. This time, the situation is different, which is why I was willing to give him credit for it instead of thinking that he is doing sort of lip service or saying it for publicity. And, I hope he doesn't try a quad this time. He deserves the championship and doesn't need to risk it.
As for Mao, all the reasons you gave do not suggest that she would have tried 3A in Vancouver if she could win the gold without it. Well, at least, you don't sound having too big an issue with practicality of it.