I think rd0 has a point (bear with me) but that point is screwed by geography...
I agree that we don't have family friendly sports climbing crags with an extensive range of routes nicely bolted from 4's to 8's etc... and I also agree this probably hinders climber development in the UK (makes it less accessible to newbies - lower grade climbers IMHO).
But thats largely because we dont have huge expanses of *sunny *dry (consistently) *good *limestone here in the UK. Most venues are smaller with a density of routes that reflects the rock type and position (i.e slab/overhanging/cave etc..) we dont really have places where there is a large 'wall space' of rock that is all of these - that would thus accommodate 8a climber and his family wanting to climb a range of things.
Thats the nature of this island!