I am proposing that making a currency decentralized creates certain limitations. Without a central authority its extremely unlikely that a monetary system built on faith will last long. For bitcoin the claim is that the network is what you must have faith in, not a central authority. I don't find that compelling personally, mainly because I haven't found the protocol to be so bulletproof that I only need to trust it and can believe that the network will hold regardless of how many bad actors may attempt to corrupt it (not saying that is happening today, only that it is inevitable with time).