You have the over regulation right. Believe it or not, I settled in here when I retired from the military because it has less regulation than most of the lower 48, and for someone who loves the outdoors it's about as good as it gets in the lower 48. I am amazed how much the government has taken over in the last 30 years or so though. Probably half of the areas I used to love to explore in 4 wheel drive vehicles 30 years or so ago are now all closed, or have exteme restrictions in place.
Even areas that are quite well managed to cover the needs of all groups are coming under a lot of pressure from the crowd wanting government ownership and closure. I would expect most of the Moab area to be closed within the next 10 to 20 years, with many other areas within the state shut down much sooner. We even have areas of the state now where you can't hike without a permit, which is hard to get even if you apply 6 months ahead of time. All of the heavily regulated areas are of course managed by the Feds, not the state.
All that said, for now, many of the good trails in this area are restricted to 50 inches or less. For the most part, many of them are by far the best places to ride in my opinion, so if you want to play there with a side by side, the 50 inch rzr is not only a great option, it's the only option