While I understand your point, I find that a surprising number of people have issues with 12am vs. 12pm, often confusing the two. These same people tend to think midnight occurs at the end of the day.
jorangreef is probably right, at least assuming that we get to colonise other worlds. I mean, what does it mean to talk about 'day' when you're on the ISS? How are Martians going to deal with the fact that they have a Sidereal Rotation Period of 24h37mins? Or the Moon, with it's roughly 700hr SRP.
This seems like it would cause more problems than it solves.
"It's 10:00 here in London. I need to call someone in New York, what time is it there?" "10:00, same as it is everywhere in the world." "So... is now a good time to call them?" "I have no idea."
I'd imagine it would be much easier to remember "business hours in NYC are between 1200 and 2030 UTC," than remembering the time difference and applying a translation every time.
And live shows would only need to advertise events in UTC. DST is almost a symptom of day/night/time discrepancy already but it's a top-down rather than bottom-up approach.