Again, no point in doing something that has no reward so the by definition is not wrong. It's is not that you cannot do it despite not being rewarded, but it is not what the game encourages you to do.
Just because you ignore to see rewards does not mean there are no rewards for exploring.
1) Found oddities -> reward
2) Found items you want to keep (equipment, ammo, uniques, crafting stuff, etc...) -> reward
3) Found loot that is easy to carry -> reward
4) Heavy loot that can be stashed in wildness and carried out later -> reward
With points 1 and 2 being actually the best rewards, that drive exploring, not stuff to sell, due to diminishing returns of sellable loot after player gets rich.
Although admitedly a very long time ago (almost in a galaxy far far away...) Starting by the tunnels, going up into the mutant infested upper area and then working all the way back, you'd have enemies respawn. As far as I am aware, enemy respawn times hasn't changed, at least I don't remember that being in the patch notes. Also literaly all enemies in depot A would respawn however the game was reduced in difficulty or maybe at the time everything there respawned for testing purposes I am willing to grant that much as a possibillity, but at least the first time you'll do it, it's hardly not going to get a respawn in the earlier areas at least...
This just shows how much out of the touch are you with the game and that pretty much everything you say is based on theorycrafting on the game that does not exist anymore.
Human "muties" never respawn. Other critters respawn slowly and it never happens so quickly that you would get respawned opponents in already cleared parts of Depot A during single run. As I said there is more then enough time to clear out whole Depot A and go back and pick up everything you left behind in a couple of trips back.