I wonder where mr. Know it all went.
As we say in this hobby all the time....if it looks Too Good To Be True....it probably is.
A better explanation of how Bitcoin really works...is to read Keynes book where he describes "Animal spirits" and their relation to economics....if you make enough people believe something.... it will happen. Enough people started to place value in a non-tangible asset that was backed by nothing tangible.....and they lost.
I still don't believe that all of that computational power is just being used to solve a single problem....call me a conspiracy theorist...but it is too much of a very valuable resource to be wasted in such a way, when it could very well be very easily be used to solve actual problems that do require that amount of computational power. Just because they don't say they are doing something...doesn't mean they are not. The absence of proof does not mean that there is no proof.