An interesting request for information.?
I remember as a babyish teen first driving. Someone bought me a sun shade for my first car and I swear that written on the wager on was a ample disclaimer: Please remove from windshield before operating the vehicle. Stupid warning have to be given so stupid relatives can't sue when they do something stupid.
..because they do...?
Because people can be stupid and so the decriminalized department at the FDA said it must be labeled so.
Just like how your hot cup of coffee from McDonald's or Starbucks say "Caution: HOT!"
because of idiots! like a packet of peanuts usually have a warning that the packet may contain nuts!
Anytime you see something transparent like that it is because twelve idiots surrounded by a jury sided with some other idiot who sued somebody for something that everyone else looks at and, resembling you said, says "DUH!"
For similar reason to that for so many warranty overkill disclaimers today. Like that ludicrous toothpaste one cautioning not to swallow it and those ubiquitous topical ointmet products that caution us 'Not to be taken internally'. Aren't those people who are stupid satisfactory to rub shoe polish in their eyes too illiterate to read the caution labels?