The answer is actually more obvious than you might imagine.
The hot shoe is not really as "standard" as you thought — at least
not for digital cameras. This is a relatively new feature for the newer
consumer-level cameras, though the professional digicams have had the hot
shoe for some time now.
Take a look at the current consumer market. Which cameras offer a hot
shoe? One of the popular ones that available right now is the Fuji 2900,
and another yet to be released is the Epson 850Z.
Notice that other very good cameras in the same class as the Sony
DSC-F505 such as the Nikon 950, Olympus C-2000Z, Toshiba PDR-M5, and
Casio QV-2000UX do NOT have a hot shoe.
It simply was not put into the design specs, perhaps because of expense
or perhaps so that these companies could have an option for
differentiation between current and future models. What the consumer
wants for the future is often presented by the company a year or two
behind our expectations.
So when we see models like the Epson or the Fuji mentioned above, some
users go ape over the possibilities, pending of course the results in the
images.
While I'm here...how about telling me why Sony's new digicam doesn't have
a hotshoe for an external flash? This feature seems to be a pretty
standard thing these days...as lot's of people like to have their options
open for the future.