Kneejerk reaction to PLD changes.

[Bright-Flower]

All enemies will just have their damage scale upward to compensate. Its like raising minimum wage, everything else goes up in price.
Also, you forget current tanks can put up tank stance, and use cover for 40%~ mitigation.
So the future 20% mitigation is still less.
(Not that I care if cover has mitigation on it or not)

Well it depends on if they were balancing enemy damage based on tanks being in tank stance or dps stance before. If they were balancing it based on tank stance there shouldn't really be much of a change at least for this reason.