His backers couldn’t figure out how to make money on wireless power transmission. If you can make it work how do you charge customers who in theory would just turn on their electrical device and pull the power from the air.
You can charge some to keep you in business, but others will steal the power and you can't block them. You're right, not a good business model.
There are already companies making devices that convert wireless energy into power for small-powered devices. We're criss-crossed with energy from various electrical fields and transmissions. Some say it's frying our bodies, although it mostly affects people living under high-transmission towers. I think we'll see more wireless-powered devices as electronic circuitry gets smaller and more powerful. For the big stuff, forget it (at least for a couple decades).