It didn't really work well with cigs until govs started banning smoking in restaurants, bars, etc. That said, the shaming was important for setting the social stage for such legal bans.

Of course they do - they modified their contract of carriage - which you basically agree to why buy a flight (https://www.united.com/en/us/fly/contract-of-carriage.html) it’s the same mechanism they use to deny you boarding if you are barefoot etc.

I don't really want that. But I do sometimes fantasize about revoking some people's ability to use speakerphone or reply-all.

Shaming doesn’t always work. I’ve asked politely and been threatened in return by people that look dangerous. That made me want to avoid confrontation in the future.