buzzard,
i prefer a mixed use outdoor experience that is almost always enabled by using my 4x4 to access remote areas. I don't own an atv, but i've put 6000 miles on my 4x4 since november on backcountry trips so i guess i can be lumped into that group.
I agree, there does seem to be a disproportionate amount of obese people, but i would rather have an obese person out enjoying (responsibly) the outdoors on an atv than sitting on their ass watching baseball. Atv riding is more of a workout than you might think. I run in a half dozen races each year (the largest being the wasatch back/ragnar relay) and the few times i've been on an atv i've been sore the next day. Not saying it's the most aerobic workout there is, but it's honestly a step in the right direction for some people.
There are also people like my father who is also is in the midst of a battle with cancer, who would love for nothing other than to go on a nice scenic hike, but is physically unable. He grew up in central utah and is very passionate about it. He has a right to access the backcountry too and can only do so from the passenger seat of my jeep. We can't be so quick to judge others because they choose motorized access. Labeling all orv users as obese, out of shape rednecks with zero respect is about as realistic as labeling all opponents of orv's as soap dodging, hair farming, patchouli wearing, liberal hippie douche's. It just doesn't work that way anymore.