I think of the small generator as more like "emergency use". The "other purposes" stuff is a bit of a red-herring if the main purpose is range extension.
But a homebrew series hybrid is going to be very inefficient, and the number of charging stations is growing daily
PlugShare - EV Charging Station Map - Find a place to charge your car!
It just makes more sense to have a beater (possibly as backup) if an ev doesn't meet your driving needs IMHO.