I rather suspect your snippet from John Kyle about the Rocheid Path is a spoof [Issue 218]. I bicycle along it with my 10-year-old son on ordinary city bikes about twice a week and relish its traditional country path surface.
In addition, I am involved in the revival of the pilgrim way from Edinburgh to St Andrews which uses the Rocheid Path. Walkers have time and time again expressed a preference for country style paths rather than universal macadam.
I wonder if Mr Kyle has established how much it would cost to macadamise the path.