I would think the average person isn't lucky enough have an inventory of multiple thousand dollars of high-end computing equipment. This kind of system would be perfect in developing countries, or as the project suggests, for education.

Many people in developing countries have mobile phones, and smartphones are rapidly becoming the computer of choice for them.

Also, remember that today's high-end is tomorrow's low-end. Why develop stuff for the past? Don't think of the developing world as a dumping ground for our worn-out ideas and wares, because that's not what it is.

A related HN post from a few weeks ago, a bit more technical: http://hackerne.ws/item?id=3916647

As the blogger suggests, this type of tech would most likely be used in internet cafe environments, or classrooms. It might not work out so well at home but I can definitely see it being used in public environments.

This doesn't seem like it's that hard to implement though, I wonder if commercial operating systems decided to neglect this type of feature fearing that a few multiseat users is a few potential licenses lost?

On top of that, the Rasperry Pi costs $25 and is full computer in of itself (which, in of itself, is a testament to the growth of the mobile system hardware market)

Slap a case on it and a copy of Ubuntu, double (or triple) that price, and you still have a cheaper option than this USB solution.