Most of the Japanese "dumb" phones are smarter than American "smart" phones.
This is an utter lie. As someone who lives in Japan and owns both a Japanese "dumb" phone as well as an iPhone, I can attest to the fact there there is no Japanese "dumb" phone anywhere near the level of sophistication and advancement of the iPhone.
Japanese dumb phones have awful menus, poor user interface design, and are not fun to use. The only reason they sell is because of momentum and people don't know anything else. Also, for the Japanese, suffering is a cultural value, so they prefer to "gaman (我慢) - persevere" through awful user interfaces and suffer together with everyone else.
Finally, as a daily train rider in Tokyo, I can attest to the fact that the number of iPhone 4's and iPhone 3/3G's seen daily is just staggering. Apple has really made a huge impact here.