Decentralization became popular in 1999 with Napster. Of course there were other decentralized systems, but most people did not know about them. Governments and others with power shut down Napster (not counting the centralized service also called Napster, which they bought the name for). They fight almost every decentralized thing we do. After 12 years, I have to ask why they have failed. It reminds me of a quote from Matrix Reloaded (the second movie)...
Believe me when I say we have a difficult time ahead of us. But if we are to be prepared for it, we must first shed our fear of it. I stand here, before you now, truthfully unafraid. Why? Because I believe something you do not? No, I stand here without fear because I remember. I remember that I am here not because of the path that lies before me but because of the path that lies behind me. I remember that for 100 years we have fought these machines. I remember that for 100 years they have sent their armies to destroy us, and after a century of war I remember that which matters most... We are still here!
--Morpheus, Matrix Reloaded
Why are we still here using decentralized systems after 12 years?