China is the proof that it's unworkable! In Xinjiang, even though everyone is "officially" on BJT, lots of shops publish hours in local solar time and that's what a lot of people use for their actual lives. If an authoritarian government can't make people use time that's three hours out of sync with the sun, what hope is there to get liberal democracies to get people using time that's eight, nine, ten hours out of sync? It will just mean everyone uses informal local time standards, and now instead of making things simpler you've blown up the complexity by orders of magnitude.
