A pretty large nit: "Twenty-one years later, SETI@home shut down, having found nothing. An incalculable amount of PC cycles and electricity wasted for nothing.

A pretty large nit: "Twenty-one years later, SETI@home shut down, having found nothing. An incalculable amount of PC cycles and electricity wasted for nothing." Negative results are still results. What SETI@Home showed was that after analysing all available data exhaustively that there was in fact no clear sign of alien intelligence to be found. That's a different state of knowledge than simply assuming the same result without examination of data. It's a result that's disappointing to some, no doubt. It is still, however, a net increment in the amount of human knowledge.