The problem, though, is that Prometheus has already attached itself to Alien from the get-go, so it can't really be its own thing with its own image. It's always going to come back to Alien and people are always not going to like it if it doesn't meet the same visual style and tone - if it doesn't "fit" in the universe.
I don't believe it could become stale if it was the same in style as Alien because a proper story with the Jockies and expanding on the weaponized Aliens and showing their true terror is interesting enough given the right care.
It's just really stupid of Ridley Scott to want to separate away from Alien, but also at the same time still connect it in a parallel manner. It just doesn't work. I dunno, It just would be nice to have some consistency, that's all.