I think there are pockets where there's little/no punting options, but they're not too far from oases. E.G. Stafford is poor but not far from Stoke. I agree with others, where the population is low (density), so are punting options. I'm in Lincolnshire these days, which is sparse; and I imagine Cornwall and northern Scotland are quiet too. The mention of Liverpool is surprising to me, just from the size of the city you'd imagine it was decent enough.