Another point to consider is coolers. During your upswing, you could get the money in good with your AA versus KK and your KK versus QQ and so on. You got it in good, but the villain can't be faulted for paying you off. Also don't forget that a great deal of money is made and lost I believe in seemingly mundane pots like ones where no one flops anything, blind steals, and the like.

As for donk bets, I like to raise them as well, because they are by and large usually weak. If you have a genuinely strong hand, why not let the pre-flop raiser put money in the pot and either continue to call and not fully reveal the strength of your hand or check raise and get even more money than a simple bet would achieve? I like to see showdowns with donk bets when I can because they are USUALLY very reliable tells in that donk bets by villains tend to consistently reveal the same thing. If a villain donks out and they are strong, they will tend to always be strong when they donk bet. If they are weak, they will always tend to be weak.