I built homes with Habitat for Humanity in Oklahoma once, and was amazed that none of them even had basements! I couldn't wrap my head around that. Where are you supposed to take cover?!
I volunteered for them now and again when I was younger, and those Habitat homes were pretty bare bones. I don't doubt the need for one at all, but let's face it.. excavating a basement then building on top of it is a large expense.