That is hyperbole. The vehicle can handle the load just fine.
With no disrespect, but it's not. Unless you have designed the vehicle, conducted finite element analysis of it, placed load sensors on the frame, and all the other engineering required to truly asses the vehicle's tow rating, you're frankly not qualified to make that decision.
Your counter example, is however all-or-nothing thinking. There is certainly a difference between hopping in my sorento and load it with 200 pounds of people and drive 30 miles, versus loading my sorento with a trailer heavier than the vehicle was rated for and driving the same 30 mile trip. There are, inherently more dangers associated with it. Also, doing so subjects your fellow motorists to potentially greater danger with the loaded trailer example.
Just because others have done it, and even if you put an admirable amount of calculations into it doesn't mean that if anything happened, your explanation and calculations would absolve you from any liability. If you feel confident that it's safe, that's great, and as long as you never touch public roads, that's fine. When your tire touches public roads, and you've loaded your vehicle more than the manufacturer's tow rating allows, you've potentially broken a law (Varies by state). Even if you haven't, should anything happen and you cause a major accident, you can bet your Afflac beak that you're going to find yourself trying to explain how you (With what credentials) are smarter than an entire corporation, and therefore are not liable because of such.
I dug up the laws in California, for example:
https://www.dmv.ca.gov/pubs/vctop/d18/vc42030_1.htm
FWIW, I do subscribe to the theory that manufacturers purposely lower tow ratings, because many people are grossly incompetent when it comes to properly towing. I even subscribe to the theory that manufacturers may lower the tow ratings for fear of warranty work due to the added strain on the drivetrain, suspension, cooling and braking system. I even subscribe to the theory that if you setup your tow rig properly, you can safely tow much more than the sticker allows...But, those are theories, and don't hold up in court, and my non-professionally-accredited theories don't make it safe for me, nor you, to rely on them (Which is why you'll never see me overtow my vehicle)