Frankly, it's because similar technology has existed for a long time now, just not with that sort of bandwidth. It's used in rural areas and such, to deliver broadband speeds where satellite or dialup would normally be the only options.
Their speed advertisements are pretty funny. They don't offer much statistics on the performance, but they say it maxes out at 1.4Gbps. That's a lot of speed, but I also am willing to bet it's their maximum theoretical. Realistic speeds are probably less, maybe significantly less so for longer distances (which it would be most used at).
You won't have this going to every suburban home anyway, so it's pointless there. You'd need a separate receiver for every house, which is just ridiculous. It's only really useful for the aforementioned rural areas.
Also, they advertise that it's much faster than what home ISPs offer, like FiOS. That may be true for what they offer now, but it's not a technological limitation. Google for instance, is trialing 1Gbps fiber connections in Kansas. That's easily fast enough to be competitive with this technology. There's no reason FiOS can't offer similar speeds, other than to make sure they have enough backend to the internet to make it happen.
tl;dr: great for farmers and hermits, irrelevant for most other people.