I hate the www thing too. The explanation is that you cannot have a cname on a root domain. They coud get around e problem by just hosting dns for you themselves.
The other issue is that you end up having t have yet another service to redirect dom.ain to www.dom.ain as well. Sometimes dns providers will do this, but not always. (Dotster doesn't do the right thing, for example.)
Awesome!
* Now please let us use naked domains, I badly need it for my startup, I hate www to death.