You also said, it "just seems absolutely ridiculous".

There are at least two elements to the answer. One is that people are bothered by it the same way they are by anything painful, disgusting, or damaging. I think that part is clear and not in the least "ridiculous", and is what I was trying to address.

The other gets deeper into thought, language, and human interaction than I can address via a couple spare moments and a phone screen.