>>1539583>ATV of similiar weight and powerThat's where the issue comes in, short of some kids quads they're generally either 5-700lb utility quads usually with an overweight rider or 400lb race quads who make up for the lack of weight with liberal throttle usage.
From what I've seen looking at ORV parks around here that allow Quads and SxS the trails become a muddy swamp in short order since there's no real reason to not ride through mud, on a bike it's an unpleasant experience even with proper tires so people tend to avoid riding after rain or through wet sections which is when it's most destructive. I'd also anecdotally say that people on four wheels tend to be a notch below two wheeled riders when it comes to giving a shit about trails but that's just my opinion.
It really comes down to the user though, people can roost around on either type of vehicle, it just requires some skill/confidence to do on a bike.