There are other, better, technologies in the same solution space, e.g. bicycles, which are more useful, familiar, vastly cheaper, more reliable (e.g. don't need charging, simpler all-mechanical design), and already have tons of existing infrastructure. Bicycles have drawbacks (e.g. the "what do you do with it" issue common to almost all vehicles), but nothing that the segway doesn't also have.
The segway solved nothing. It was a neat toy.