Eh, kinda a stretch to make this about Americans.
In the original thalidomide problem it was the same 'paranoia' that kept it entirely off the market in the US.

Beyond that, I'm not sure I get the reasoning behind "Americans are so dumb that they put safety and usage instructions on cancer medication, with emphasis on the most severe warnings!”
Why wouldn't you want to label dangerous things that are actually, uniquely hazardous?