>>1383472because it's awesome? at least to me. not only i enjoy much more everything, from nature, to doing long distances to the navigation of a hard trail, but also i find my riding is smoother in the mountains and i got less tired on long rural roads..
that said, i don't get stupidly stoned, i don't race, i don't ride stoned on busy streets or roads, and i usually ride alone so i don't get to be an annoyance to anyone