Yeah, this kind of thing lead to some recriminations as a kid. Air conditioning was rare, many shops were small and had no seating, so the right thing to do was take your cold soda outside. But it the weather was so hot that it could be warm before you finished a bottle.
A few nice adults told us that it would stay cold a lot longer in a paper bag, and that a plastic bag wouldn't help. Both statements proved true…but most other adults would assume it was alcohol. They'd be scowling at us, telling us off. Sometimes we'd show the bottle, but few even need to smell it to be sure it wasn't alcohol.
Even then, most of them never started acting like they were the ones who had been in the wrong. All because some people were known to use a paper bag around beer bottles.
I live in Baltimore and I see a lot of people drinking singles out of a paper bag on the corner or their stoop. I've seen it on the bus, too.
Might be more of a hood corner store thing than a rural guy in a pickup buying a beer for the drive home type thing.