It seems to be in the same bucket as people not wearing seat belts and making fun of you if you ask them to wear one in a car with you.
If it's not something everyone does, and if you mention you do it for safety, the reaction is often rather negative. I think people don't like the idea that they might have been doing something very unsafe this whole time.
Well if I'm passenger in a car with someone who won't wear seatbelts then my reaction will become rather negative until they put the damn things on. If we got in a car accident, I may be secure with belts, but I don't want their body parts flopping in my face either.
If it's not something everyone does, and if you mention you do it for safety, the reaction is often rather negative. I think people don't like the idea that they might have been doing something very unsafe this whole time.