Yes, my hosts also find it odd. I haven't been keeping very strict watch, but I'd say most of the people wearing them are young, and most are female. I can't say I find it disturbing, but handrails notwithstanding I've always taken the attitude that you have to eat a peck of dirt before you die. (This works out at about a pint every five years.) Coddled immune systems never grow up strong and healthy.