To be fair, gwm, I don't think that you would think that the problem was being exaggerated if you had to clear up the mess afterwards.
Having said that, in general terms I believe that you are correct - it is as usual a small minority spoiling it for the majority. And in my experience, some of the worst offenders for litter and the general despoilation of wild areas are farmers, our so called 'Guardians of the Countryside". The proliferation of quad bike tracks over sensitive areas springs to mind, as does the inevitable tatters of silage wrap plastic adorning barbed wire fences.