To do what, make terrible power metal? If success were the problem they would be doing something different with their time.
An example of a British band that's beyond awesome is Akercocke.
It's not just a British phenomenon either. Lots of bands release one or two albums and then fall off severely, losing the way. When you're in a mental place required to make good metal, you may not be in that same place two or three years later, and if you are the "scene" has most likely changed.
A lot of bands are still out there making 1988 thrash. I'm listening to one right now-- Stone. Trouble is, the kids aren't listening and so you end up with this sort of tongue-in-cheek retro headspace.
Then there are the guys who are still True when they're pushing 40. I find something suspect about that. Example: Decker from Anal Blast just got a pentagram tattooed on his head. A HUGE pentagram.
Good luck with ALL that, Decker.
I think maybe it's better to release a few really killer albums and then quit before you become laughingstocks.