Bitcoin is not a substitute or alternative for conventional currency, and cannot become one. It cannot operate as an effective medium of exchange, unit of account, or store of value. Its use in crowdfunding is a gimmick. Like the 17th century Dutch tulip mania and other bubbles, this will burst sooner or later and the adventure will be over.
Those Asian central bankers and other regulators who have imposed curbs have been wise to do so. With China and South Korea leading the way, these authorities will find their prudence justified when the inevitable disaster strikes. Officials in the U.S., Japan and other jurisdictions who have stood to one side in the face of the advancing wave of speculation should put on the record an unambiguous opinion that this is a bubble which will end badly.