Well, I'll re-hash here: I argue that coolness is something that must be earned one way or another, it's just that some people feel the need to use material possessions to make up for lacks elsewhere in their lives. It's true, isn't it?
Then there's the general perception that bikes are a lower social caste thing, and adding an electric part somehow lowers the coolness factor. The consequence is that only inherently uber-cool, open minded people can feel comfortable riding ebikes.
Regarding the faster = safer argument that's been brought up: regardless what stats you look at, the hit from behind accident is consistently extremely rare, when it does happen it's usually at night to a cyclist who doesn't have the most basic safety equipment after brakes (lights). Stats show that accidents happen most often at intersections, either in front or from the side. My experience confirms this.
Over the past few years I've had a few close calls, but not one of them involved being hit from behind. Most of them had to do with intersections, in some cases it was because I was riding too close to the curb or on parallel bike paths (cars look for traffic in traffic lanes, not next to them) But, mostly they had to do with cars pulling out in front of me or cutting me off after having under-evaluated my speed, and with a non assisted bike, mind you.
To be fair, I do ride a good bit faster then the vast majority of cyclists I cross and pretty much always race anyone going close to my speed, most of those reply in same. I can imagine cars would expect scooters / motorcycles to be going at same speed as other traffic and treat them accordingly, but mostly they appear to expect bikes to be going at average bike speeds.
Washington State Bicycle Collision Data for 1994 to 1996:
http://www.bicyclesource.com/images/was ... -study.pdf
Ken Kifer's got a good writeup on bike safety, with lots of stats:
(It's also a good cycling resource page, pity he got pwned.)