In my part of the US (I suspect thw whole country), such a basic
commuter bike is answered by the cruiser. 26" wheels are ubiquitous,
as are single speed coaster brakes. I can understand the concern over
aesthetics, but they fit the bill. I agree that the three speed hub is
a remarkably practical transmission for most practical bicyclists. And
a plain old single speed coaster brake is perfectly acceptable for
many folks.
I like your spec for a commuting bike. The closest (reasonably priced)
thing I've seen is this one a LBS sells these for about $160:
http://www.micargibicycles.com/bike_view.html?bid=elegant_m
They also have step though frames. And a very similar less expensive
SS freewheel equipped with front/rear V brakes.
Seems decent enough. A front brake is necessary, IMO. And I suspect
it's be difficult to market anything other than 26" tires on such a
bike, that size has so much momentum among such riders.
Even at $160, I think it's too much. It's competing with $60 *mart
MTBs, like the one Carl Fogel is riding. I see these things being
ridden in the streets every day, often half busted, stuck in one gear.
Good enough, I suppose. Seems it would be much more sensible to make
one of those with a coaster brake hub SS or three speed, instead of
the marginal derailer systems they employ.
SS coaster brake hubs are cheap and reliable enough. But three speed
hubs are just too expensive, even in high quantities, would represent
half the cost of that *mart bike. Shimano, SRAM, SA, all are too
expensive. Korean company, MBI World,
(http://www.mbiworld.com/mbi/html/mainproducteng.html) seems to be
interested in the low end hub gear market, with apparently unproven
designs/vaproware. The reamergence of the three speed hub would be a
good thing for commuters, I think.