I always got the feeling that tanks-stack-defense-until-they-can't-be-crit was an unintended thing. Not that they totally hated it when people realized it could be done, but that they didn't build the game with that possibility in mind from the beginning. Personally, I think it would be fine to bring back crits and crushing blows both, with them just being a proportion of normal hits taken, perhaps. These "bigger hits" aren't a bad thing, just so long as they're part of the expected amount of damage everybody is taking. It's when you have abilities that allow you to sometimes or always prevent them from happening that the damage of *normal* hits has to scale way up, which makes the "big hits" practically unsurvivable.
Learn to science and stop theorycrapping in its tracks.