Hands are wonderful for decoding thought into action, that's true, but for example, the brain can imagine images way faster than hands can paint them. A lot of people can be limited by their hands in gaming too. This is exchanged for learning some kind of encoding scheme that translates thought into bits. It's also really difficult, for example, to create 3D models on your phone just using your hands.
By sending bits, the interface changes and you aren't really burdened with UI navigation or UI mechanics like touch, drag, etc. Something like a phone would take on more roles that are currently filled by desktops and laptops right now.
But again, output isn't interesting. The low bitrate is just to illustrate that it isn't that interesting compared to the other direction (but I still think there could be useful products if the device is discreet and convenient enough -- I'm definitely not wearing a full EEG headset every day).
A product like that would be a good checkpoint in scientific developments of decoding the brain too. I think it's going to be a necessary step to develop before we get the other direction though.