I look to it more like not needing to use a level 80 rotation for level 20 content. If you want to do that, you do you, but the presumption that difficulty should be scaled up for this possibility is obviously a detriment to the legit level 20s. Otherwise, with how frugal AoE options can be below level 40, I imagine a good number of jobs would appreciate having their moves available, albeit weakened, for if they do roll into an older dungeon.