It's all about awareness. Plus, I've read some "biker" carry bags of ball bearings -- throwing a few evidently gets a car's attention. Not advocating that, but...
If there were more signs on busy highways that alert drivers to the presence of scooter drivers and motorcyclists, maybe both would become more practical and less "frightening" for daily use.
I saw a scooter splitting lanes on the freeway in California yesterday. Gutsy but necessary. The side element to this is that drivers in cars and trucks are going to have to be more aware.
I'd love to ride a scooter around if everyone else was on one too... but being with so many cars and large trucks freaks me out!
Personally, I would rather ride a big, glitzy bike to work, but I definitely understand the appeal of scooters. They are like the bike equivalent of Smart cars.
When I lived in France for a few months, I noticed that scooters were everywhere. They seem especially convenient when you live too far away from work to walk, but close enough to work that it seems almost unnecessary to drive. Good way to save money on gas too!