I have found that airing down really helps a lot but many folks don't want to go through the hassle. It takes a while. Some of these folk store their truck in the area so I would think there would be little need to air up. I drive up there from El Paso so I am there for 2 -3 days minimum. I air down as soon as I get there and air up just before leaving. Also, some do not air down enough, especially in the lightly loaded rear tires.
Additional weight is not a bad idea but tough to do when you are out there camping, a hundred miles from home. Whatever is back there will get beat to .... , not if but when it does start hopping. There is plenty of sand to shovel into the bed though, if you are really feeling froggy.
True, but where there's a will there's a way. I've gone a lot farther in 2wd trucks than anyone ever thought possible simply by adding weight to the rear and picking proper lines off-road. 50-lb water softener salt bags are durable for short trips and cheap enough to justify buying several hundred pounds' worth to make rear suspensions flex properly. Sandbags are also cheap but involve a bit of labor to fill...but can be filled once on site, placed strategically in storage areas to provide weight for traction, and emptied before your trip home to save on fuel. I always secure weights so that they don't get thrown around; tie-downs, ratchet straps, and even chains are fairly inexpensive at Harbor Freight. My Deuce now has an additional 220+ gallons of fuel storage in the bed, a large truck toolbox, two spare tires/wheels plus a tire crane, and still has room for cargo...but this adds a lot of beneficial weight off-road and I typically don't have to add anything else. I find that the suspension flexes quite well with this added weight and I get virtually no wheel-hop with it. YMMV.
At least once a year I join a group of co-workers for various off-road expeditions through Death Valley; most involve at least one winching point and LOTS of sand/rocks, so airing down properly is a MUST. Inexpensive valves can be added to valve stems to speed up the air-down portion, and air hoses with quick disconnect chucks can be made on the cheap with used gladhands for airing back up. I've had to fix too many parts broken in the past from wheel hopping, bouncing over rocks, etc...so airing down and managing weights on a vehicle are FAR easier than expensive and/or time-consuming repairs later from taking the earlier shortcuts.
But I agree with you; some people don't want to go through the effort and will pay more later, that is part of the learning curve.