>The human capital freed from innovative technology can be utilized some where else. That free time can be used to invent new things or focus on some other problems that make our lives better.

This sounds great in principle, but when it comes to paying the bills, the average person does not have the ability to make money doing this. I personally think universal income makes more sense from an economic standpoint. However Gates' solution is likely easier to achieve political and also solves the loss of purpose than many people feel when unemployed.