Only 42% of Utah is Mormon these days. Are you saying that 58% of the people you see walking around are very clearly not lds?
There are a lot of people that have similar grooming standards. There are tons of religious groups that have similar moral standards. And there are a lot of people that don't drink because they don't like it or don't think it's healthy, regardless of religious beliefs. Tattoos are now fully allowed by the church, so even that doesn't really differentiate that much anymore.
I think those that feel like it's clear who is and who isn't would be very surprised if they actually knew instead of assuming. And you know what assuming does.
I believe that what people are experiencing is the vocal non-member minority that feels like the large majority, but just isn't.