+1 what ninfan said. Had similar here with newer riders complaining that a popular (completely natural) trail was too hard and that we should sanitise it. Those who use it regularly pointed out that there were plenty of other trails on which they could build up the skills needed, and that as the trail runs through a nature reserve we only have the right to ensure a basic level of access (clearing fallen trees and such). Much huffing ensued and a pretty respectable flounce by one guy who swore off cycling forever because of our horrendously conservative attitude.