Silliness. Not all new trails are robotrails, and even if they are, you can still walk on them. Around here, far more trails are cut, and especially maintained, by riders than not. I doubt most multi-users don't realize that at all.
http://m.pinkbike.com/news/opinion-paying-it-forward-2015.html
http://m.pinkbike.com/news/opinion-paying-it-forward-2015.html