First, it is an ethical problem. The idea of producing things is not taught in elite colleges, nor is the idea that it is possible to make a positive contribution to society (e.g. rms) without becoming superrich (no offense to those for whom this is their primary motivation).
Second, a lot of the products of which the GDP percentage is based upon simply involve repackaging and selling debt. (e.g. http://ow.ly/1sf8Rp ). In other words, a lot of the economy is based upon accounting tricks.