The hitch in the bumper isn't rated for towing, it's most likely strong enough but the manufacturer doesn't want the liability if something goes wrong.
You can still attach an under the bumper type of hitch if you're concerned.
"But it does me no injury for my neighbour to say there are twenty gods, or no god. It neither picks my pocket nor breaks my leg." - Thomas Jefferson, Notes on the State of Virginia, 1782
Arguing with a truck driver is like wrestling with a pig in mud, eventually you realize the pig enjoys it.