Good thing the point of these device is absolutely not to earn revenue through mining subsidy
The description of 21 Bitcoin Computer lacks solid vision of its purpose, maybe you could explain what IT-industry niche this device will shine in?
If the concept works, it might create a brand new one. Think of these devices not as an end product, but both a tool with which to build something and the foundation to build it upon. If something like this, or a more advanced version down the line, is integrated into various electronics, the result is the 'Internet of Things'. If it works, that is.