Other.
I like riding bicycles, it carries with it a sense of freedom, owing to its exposure to the elements, lightness of vehicle, and relatively simple technology. Even someone as mechanically challenged as myself can do basic work and maintaince on the "vehicle", whereas with a complicated car, getting more and more complicated every year, I am at the mercy of spiffs who could be telling me anything to line their own pockets. I was once charged $30 for radiator fluid as part of a normal scheduled service for a car I owned - just a small example of the ingrained racketeering which comes with the car culture.
Added to the sense of freedom of a bicycle are all the regulations surrounding cars, such as registration, license, speed limits and parking. A little assistance in this sense of freedom which does not involve bringing the government onto one's own back to burden the ride explains my interest in electric engines and presence here. The ideal cycling world doesn't have big hills. Electric engines help to iron out the imperfections while still retaining the essence of the cycling experience, depending on the type of electric assistance.
Part of my attraction to bikes is my aversion to car culture, whether that be the egotism tied up in the image of a car, or the dominance of the car in cities and towns, which deprive people of living and community space, creates noise, unpleasant air to breath, friction between people and stress generally. Then there is all the killing and injuries. People, particularly children, are constantly in danger from cars.
Most importantly, speed is relative and everyone would gain a great deal by slowing down a considerable pace, smelling the roses. They are out there. It seems a shame to be rushing by them all the time. If everyone is going fast, no-one is moving ahead of anyone else. Might as well take it is easy and relax a bit.
Ironical that having all the physical work done for oneself in the way of a combustion engine is actually more stressful than doing it yourself in the final equation when all is considered.
I also just like electricity. Bicycles and electricity are two of man's best inventions. It doesn't seem like a bad idea to combine them.