I am greatly in favor of new trails built by the community of mountain bikers expressly for mountain bike use. That's not a bad thing at all, as long as the trails aren't sources of erosion or degradation of the environment.

Many trails for hiking and equestrian use were built in whole or in part by volunteers from the hiking and equestrian communities and these communities still contribute time and effort toward their continued maintenance. Seems like a good opportunity for mountain bikers to develop a similar feeling of trail ownership and stewardship.