The consequences of what money is in modern economies, are not well understood or accepted. I suspect that the possibilities that this open scare a lot of powerful people.
If somebody want to dig further in the rabbit hole, I recommend:
http://moslereconomics.com/wp-content/powerpoints/7DIF.pdf (this one is a pdf)
http://neweconomicperspectives.org/modern-monetary-theory-pr...
a) a "heterodox" theory that mainstream economists don't consider entirely legitimate, and
b) precisely how central banks in the US and UK describe their own routine monetary operations.
I still struggle to understand how and why these statements can both be true.
And MMT has another interesting property: when you take the time to learn a little, it makes a lot of sense.
They have been always saying how money is really created, now the Bank of England confirm it, but we should keep believing the text books from the gold standard era I suppose.
But it's possible to see some progress. There is now even a textbook for university-level macroeconomics students:
http://www.amazon.com/Modern-Monetary-Theory-Practice-Introd...