The mapping is clear, and I think many of us get it that anyone in any time zone can look at the mapped clock and see the same time.
As well, I personally think that building on UTC but making it clearly recognizable is a clever approach (avoiding, as you say; “Meet me at to 2PM UTC.” being quickly internalized in someone’s brain as 2PM local time), but there are too many (known) edge cases that this cannot solve (such as arbitrarily-numbered minute offsets, and possibility of confusing dates when setting the time)
As well, I personally think that building on UTC but making it clearly recognizable is a clever approach (avoiding, as you say; “Meet me at to 2PM UTC.” being quickly internalized in someone’s brain as 2PM local time), but there are too many (known) edge cases that this cannot solve (such as arbitrarily-numbered minute offsets, and possibility of confusing dates when setting the time)