Very good point. I always ride on a mountain where the drainage is pretty good except in a few small areas. I never get that tons of mud stuck to the bike thing.. it is more like being saturated with a muddy spray. The loggers do 10000000x more damage around here than anything. Around here most ruts and problems caused when it is wet simply get smoothed over by the mountain bikers themselves while riding over it for a week.
Sometimes I wish it were drier. However, riding through mist can be pretty sweet, or days when I can get above the cloud cover and look down on the beautiful Odenwald.