FWIW I think the 12-28 or even 13-32 is a more useful combo for most riders, and I don't know why bike companies don't spec this on more bikes (or even offer it aftermarket). Same with sub-compact chainrings. Most people don't even need a 50, and a 34 can still go very fast. I think a more practical gearing for urban commuters and touring/adventure/enduro road bikes would be more like 32/46 with a 13-32 cassette. This would allow the largest usable range for 80% of bike riders while maintaining tight gear spacing.

My commuter is currently a 1x7 33Tx12-28 in the rear (it's an 8 speed cassette with the 11t locked out due to frame clearance). At 120rpm it does 26mph, which is more than I need considering the full fenders, rack, trailer hitch, and dual panniers. It still climbs well under load and has a very simple and elegant drivetrain. I'm actually considering a cheap 12-32 8 speed cassette which configured for clearance would give me 33Tx13-32 7 speed, nearly 1:1.