Really curious what Boosted Boards' 'bigger ambitions than making skateboards' are! A friend has one of their Kickstarter boards and it's unreal.
The folks that could really benefit from a solution are the elderly, physically disabled and young kids. For the life of me, I would find it difficult to see the majority of these folks riding a skateboard.
Even assuming infinite battery life, what's the form factor? A wheelchair won't cut it. A Segway-like thing won't cut it. A unicycle won't cut it. A conventional bicycle won't cut it. A recumbent bike or trike won't cut it. Roller-skates won't cut it. Exoskeletal legs won't cut it. Many of these things are of proven usefulness, but they've never been general-purpose substitutes or augmentors for pedestrianism. A version of some of the above which folds into something unprecedentedly small and light might begin to cut it, but how is that achievable within present-day engineering constraints?
You only need to solve the problem for the majority of people ( >50% ) to be considered a good solution. The solution may prove to be elegantly simple.