The traditional 'public footpath' no longer exists in this part of the country if it runs through woodland or heathland. It is either being ridden as if it were a bridleway or has already been converted into a bridleway.
The law about riding on footpaths is and always has been very simple. If a footpath is ridden, the only offence committed is one of trespass against the landowner. If the landowner does not take the matter up with the riders (which is impossible to do because no landowner can afford to police his estate on the necessary scale), the path can be turned into a statutory bridleway after 20 years of unauthorised riding. This is sometimes done so surreptitiously that it goes unnoticed.
Fifty years ago riders wished to be in good standing with both landowners and walkers. They would no sooner have ridden a public footpath than have gone to a party with open fly-buttons. Today's riders are very different. They ride footpaths brazenly, knowing that nothing effective can be done to stop them.
After a period of unauthorised use, riders combine into well-organised local pressure groups which 'legitimise' the situation by 'upgrading' the footpath into a bridleway.
Riding is still an elitist pastime. A genuine regret is that those portions of the community who previously upheld the spirit of the law for the general good now manipulate its letter to achieve selfish advantage over the less privileged (which walkers clearly are).