Well, it's a bit of a stretch from my "there are some other digital cameras already with physical dials for some functions" to your "the G series is designed great", and I don't think there is much more that needs to be said about that.
As far as DSLR design is concerned, they mainly follow the same design principles that film cameras had already adhered to for over a decade after the late 1980s. If you look at a 1986 T90 with a data back, you have modern DSLR ergonomics in a nutshell, a quarter of a century ago. Practically all camera makers increasingly moved away from dedicated dials already during the film era. There was a good reason for that, which is simply that as soon as camera functions exceeded the complexity of one-dial-per-function, the old 1950s interface began to break down ergonomically. The photography world at large accepted this design change; by the mid-1990s, well before the advent of DSLRs, most newly-designed film SLRs already were shifting from dedicated dials to software-controlled programmable dials, and customers largely appreciated this shift - otherwise, for example, the newly-introduced Canon EOS series would have tanked, being completely built around this new user interface concept, instead of becoming the market leader.
A look at Leica is very instructive. A lot of people seem to associate Leica cameras with traditional, one-dial-per-function interfaces, but this is really just a tribute to the ideological stance of the retro-loving parts of the customer base, which can nowadays be considered proven allergic to changes, and the technical limitations of the M platform.
However, take a look at Leica's really high-end cameras. By this I mean not the M9, which basically caters to affluent enthusiasts, but those newly designed exclusively for working professionals, such as the S2. The latter has exceptionally clean ergonomics; it does have a dedicated shutter speed dial, but everything else, including setting the aperture, setting ISO etc. is done in software using a thumb wheel. The interface in turn can be heavily customized to suit the preferences of the photographer On the S2, dedicated dials would have resulted in a cluttered interface, but without the dedicated dials, the S2's interface design is cleaner than that of the M9, in spite of providing much more powerful functions. In other words, it's exactly through doing away with dedicated dials that the S2 has such outstanding ergonomics. Before embarking on a highly risky development venture, I think Leica made pretty sure they knew that this is what professionals want.
