it's a dirty job, but somebody has to do it

Walking these trails after a rain is not a clean thing. But just imagine walking these trails in boots, or trail shoes. You have lots of clean-up, caked mud, and if you let it dry you have rock-hard dirt in the tread of your boot/shoe soles. Then you have socks to be laundered. Clean-up after a barefoot hike is a cinch... let the mud dry, brush it off, and then a quick garden hose or shower eliminates the residue. Done.