It wouldn't work for me because, although I do commute in the car I drive, I very often do other things with it as well. I have a set of golf clubs in the back of my CR-V today, because a couple of us are playing after work. I sometimes go to the hardware store on the way home and I wouldn't be able to fit much in the back of an Elio. I often toss a bicycle or lawn mower in the back of the car and go ride or mow. Heck, I found full-size sedans to be too limiting for me, let alone a 3-wheeler, and switched to something with a liftgate.
If I had an Elio, it could be used only for a commute to-and-from work, and I'd probably spend more time on the road in the end because I'd have to go home to get my other car to run the errands or do the things that I couldn't do in the Elio.
It's one of the reasons I don't have a motorcycle. I don't have the desire to have that much money tied up into a limited-use vehicle.