1) You can take the electric more places. I'm not hassled on sidewalks, canals or the MUP, as long as I'm considerate and going at a reasonable speed for those scenarios.
2) You won't stink like lawnmower fumes when you get to your destination.
3) You won't gag out people like me, who have to hear the noise and smell your fumes in the bike lane. There is a guy around here who rides one of those. While I'm curious, I'm also kind of grossed out.
4) You won't have to make an extra stop at the gas station.

...However, I am in agreement with an earlier poster who notes that long distances may require gas. Distance is the main limitation in electric technology right now. Otherwise, I'd be buying an electric car also.