More like a moped actually. :-)

Where is the point in cycling if you don't have to use your own muscles to ride?

Because sometimes you have the energy and sometimes you don't. Sometimes you're ok with sweating and sometimes you aren't. Some days are 100F degrees and some are 60F. Maybe you're not strong enough to maintain your speed up a hill by your house but you're ok for the rest of the trip. It might lower that one part of the trip from "too hard" to "doable" and it's one more person getting more exercise and driving less.

It's good if everyone bikes more but the whole point of a commuter bike is that the exercise part is secondary. First is getting from point A to point B daily and conveniently.