Humans, are animals. And like all animals we belong outside. The only reason there is an inside is because at one point we needed a break from the ouside. Then we spent so much time inside that going outside seemed wrong.
Our ancesters shaped everything around them because as a species that is what we do.
The idea that riding through the woods on bikes is doing any measurably comparable damage to this planet is beyond logical reasoning. We have crossed this planed with concrete roads, but a dirt path 2 feet wide is somehow going to topple mother nature?