When I go back to an instance to grind for low level gear, I don't want to rebuild my characters. You get no XP from lower level instances so why require people to "gear down"? If they want to nuke the place from orbit (*it's the only way to be sure*), why do you care to stop them? You already have the lock system in place so they can't run it 10 times in one day, it seems that would be sufficient to prevent abuse.
It's to never trivialize farming mostly i think. Speaking as a power gamer if i could nuke something from orbit i would but it would bring me less enjoyment then having the game tell me "you know what no you don't get to just nuke it play it at a reasonable difficulty and have fun!". This also entices me as it lets me figure out how to try and nuke it with a well geared but low level party. As a example i had a party before my first reset that finished every map up to lvl 10 in less than 6 turns often 4.
I would agree that it's useful to allow us to nuke lower levels at full strength. It's really the only way to get a feel for exactly how powerful you've become. I like to go dominate lower levels that I used to struggle with, as a way for me to gauge my progress.
The game was designed to make all adventures, from start to end, worth replaying. "Value," though, includes "actual utility that has an impact on gameplay and thus requires balance." They did this by setting all loot to sell for the same price, no matter the level: it depends only on rarity. Further, for basic strategy, you need items to fulfill all equipment requirements ("power tokens"), and therefore you value all loot. You already get to keep multiple "bonus" levels when you replay a lower-level adventure, so they ARE easier for you. But allowing you to "nuke" means allowing you to destroy your game's economy. Yes, I know there are "cooldowns." THOSE are there to encourage you to have fun playing different adventures (and to become a better strategic player). But with this, still, allowing you to "nuke" low-level adventures would just mean that a pile of them (say, levels 2-6) would be obliterated instead of the same one over and over.
