For example, in Europe, the iPhone will be 3G because it is widely deployed. If you want to blame someone, blame yourself. Our collective apathy regarding our telecom infrastructure is exactly what give companies like AT&T; the power to sit back and do nothing.
There are no really satisfying answers to that question. Mobile devices are all about trade-offs. In this case, battery life & form factor won out over 3G. It's less than ideal, to be sure.
As noted, it was the availability and coverage area that prompted the decision. FYI: The SIM card in the iPhone says 3G on it! I just wish they could have made it switchable the same way it can go between WiFi and EDGE... so that it would first choose available WiFi, then 3G, then go to EDGE as a last resort.