Because of the reason mentioned before
You could do that just by sitting on the start screen a really long time.
Though I think Bloodborn actually banned doing this because of a bug where if you left the game on running for like 12 hours the RNG would literally stop working and thus everything would be the same no matter what.
It's cool but no one wants to wait for 12 hours.
I'm quite sure that this would work with XXL, too. But yeah, then I would be against it, even if it would "only" be an hour. Waiting stupidly is shit and if you always have to setup that long for a run you'd never run :/ a few secs/minutes, okay. But nothing long
Or if you have a file that let's you set up RNG for a new run, that would be allowed
Some would ban that as well... xD
But if we find a way to set up RNG via a precious save file we really should allow it as it improves the run for everyone.
I think Pokémon allows this... Or something like it
Don't remember how it worked in Pokémon red.
But RNG manipulation is a big part.
Is there actually any place where RNG Manipulation would be any helpful? We either just skip them, combo twister them or they're too few to be worth it
or not very random like at the beginning of Greece, for example
we actually only really fight three fights in Greece as well as one fight in Helvetia
But that's because my game is messed up
why? You think your Romans spawn differently than ours?
No, it's the circle in Normandy