This was the point of my previous "perfect DSLR" thread...I'd love the manufacturers to take a few steps back and offer simple, sturdy, ergonomic, and classically styled cameras for people like us. Rangefinders too of course!
We are not a significant part of the DSLR market, though.
Its all about marketing and market share. Lets take the simple rule for Canon IQ and Features:
xD(IQ + F) > xxD(IQ + F) > xxxD(IQ+F) must always hold true, where xD is the model number.
For Nikon, the D3 MUST have a better pro spec than the D700, then the D300, then the D60 etc etc. Its the simple rule of marketing. Given, that Nikon are grabbing pro market share from the 1DmkIIs et al, the next logical step was to target the pros back up camera, the 5D...tada...its the D700.
So whilst you think that the D3, D300, 5D, e-3 etc are all too big, the real reaon is that they are not aimed at you.
However...on the other side of the coin, the other market growth is not in P&S but in small DSLRs with kit lenses. Again, it is not you or I that dictate the size or the features these cameras posses, but Mrs Jo Public who will never buy another lens, will shoot jpeg and needs all those scene modes to be creative.
We must applaud Leica, Canon (G9), Ricoh, Epson (historically), Sigma, Zeiss, Fuji and Voigtlander for making cameras that niche enthusiasts use...but the profit won't necessarily be big here compared to pro and consumer segments.