people believe all sorts of insane things. but believing something dumb doesn't increase your risk of infection.
i saw a blurb yesterday from a paper on mask use that claimed 80% mask use was nearly as effective as 100%. and 20% nearly as effectless as 0%. i didn't follow through to the paper, so i can't vouch for the math, but i think the concept applies. it doesn't matter all that much if a small minority of people are reckless. the rational behavior of the majority protects them too.