Plus, the target market doesn't likely have storage space for both their existing bike and a pedal assist model. If I'm a city-dwelling hacker, I'd prefer buying a wheel over a scooter. I just pulled up listings on Amazon for inexpensive e-bike pedal assists, and they're mostly largish scooter-types that take a significant footprint to store compared to a bike which I can hang on my wall.
Plus, having a wheel allows me to continue using my tires, frame, accessories and everything I love about my current commuter bike.
Also, I would use the e-wheel during the week for my commute to work and come the weekend I could fairly quickly switch the wheel over to my regular one and exercise properly. One bike, two purposes.
That's true. One of our neighbors used to take out the front wheel just for storage when he got out of the elevator. There's just no room and folding bikes are still a little expensive (unless you're lucky enough to score a used one cheap that needed a bit of TLC).
Plus, having a wheel allows me to continue using my tires, frame, accessories and everything I love about my current commuter bike.