It solved problems for cities and city planners. A Segway user could be like an enhanced pedestrian. You could have fewer stores serve a larger populace. It didn't get to do this because it didn't solve its own chicken and egg problem.
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.
