One reason is that I'm allergic to the oily fumes of a two cycle engine, and hate mowing with a charcoal filter mask.
Another reason is I get tired pulling the chord around with my electric mower.
Third reason is that I thought it might be good exercise.
Using it, I can tell that I sit on my butt too much, but it is good exercise. I still can't mow much more than a 4th of the front lawn at a time. And you can't let the grass get too high between mowings, cause it is just hard to push through. But I like how it sounds, just the whirr of the rotor, no loud motors. And it does work just fine.
I might kid myself about doing it cause it's a green thing to do. But I'm really doing it cause it solves a problem.
But boy, I hate to mow. Almost as much as I hate washing dishes. But not quite.