1) competition - first one to see something unusual and call it out, gets brownie points
2) now there's something to use 3,000 words on discussing in social context (my daughter will put it out as "what's the harm" or "each to their own" etc for the group to chew on)

The trick is for us to smile, be polite, maybe great them, let them know we are friendly, then eventually they will educate their friends