You just gave enough of a reason for me. If you lived somewhere where you could ride with zero traffic, sure. But I'd be even less likely to use one of these on a trafficked road than I would a regular bike. You're basically describing a vehicle that consumes an entire lane, everywhere, all the time, yet is incapable of exceeding 15 or so mph, and leaves the occupants wholly exposed to the elements. If you think you'd be unwelcome on the road when riding an upright, I think you'd be in for a nasty surprise when using one of these.