Detroit is also ruled by lawyers...foreign automakers aren't far behind though.
Smaller, lighter trucks especially do not perform well when all the weight is on the rear axle and it is a "light duty'
vehicle like a 1/2 ton.
Mark it down to safety and "CYA" from the mfgers.
Forget them for a moment and remember "due diligence" means YOU need to understand GPWR, axle GVWRs, Tire sizes, inflation, sway bars, and all that and at the end of the day....if it all adds up OK and THEN you add 32 gallons of gas @ 8 lbs and a couple more jerry cans, 20 gallons of water, food, drinks, personal items, a passenger or two, the dog and think you can STILL tow a boat behind the vehicle...then you didn't do your "due diligence" did you?
Always buy more truck than you THINK you'll need and then try to keep from overloading it. I think it is better to tow a trailer behind the truck than put too much weight on that rear axle...remember, if every car on the highway hits their high beams at you at night, your front end is riding high...because your rear end is sagging under the load.