If its not illegal to have fire rings, then don't take matters into your own hands and go destroying/removing them. I more than agree that some areas have far too many fire rings, but that's why its the Wild West here in Utah... we can. Cookie cutter camp spots, picnic tables and tin-can tourists need not apply.
If you fear an area has too many fire pits, contact the local land manager be it BLM, FS or NPS, they will gladly ask for your help if they think an area needs dispersed site control. If its really
that bad, condense 4-5 fire pits into a single one, but don't assume they need to be eliminated altogether.
Sorry, I've gotta ask since you don't list a location. Where about are you from?
See, Utah truly is different, we still have giant acreages of federal land that are open to cross-country travel, bon-fires, shooting, bombing, hunting, fishing and general desert debaucheries. It honestly scares travelers from out of state and sometimes they think they need to help reign us in... but that's not the case. Utah's citizens have been recreating since covered wagons and feet were the primary sources of travel, I think we've got it under control