No, none of my business (unless it was something i’d organised).
I rode bmx street/park/trails for years without one so havent got a high horse to get on.
Used to be involved in a BMX race club and had to tell a few then, but that was more a club rule/insurance thing.
These days i’m more likely to just mutter to myself :-).
It feels pretty weird to not wear one now on the odd occasion i ride to work/drop the van at the garage and forget to bring one.