I think a recent article on The Economist summed this up best.
http://www.economist.com/news/finance-and-economics/21576149-even-if-it-crashes-bitcoin-may-make-dent-financial-world-mining-digital

Yet for Bitcoins to go mainstream much has to happen, says Fred Ehrsam, the co-developer of Coinbase, a Californian Bitcoin exchange and “wallet service”, where users can store their digital fortune. Getting hold of Bitcoins for the first time is difficult. Using them is fiddly. They can be stolen by hackers or just lost, like dollar bills in a washing machine. Several Bitcoin exchanges have suffered thefts and crashes over the past two years.

As a result, the Bitcoin business has consolidated. The leading exchange is Mt.Gox. Based in Tokyo and run by two Frenchmen, it processes around 80% of Bitcoin-dollar trades. If such a business failed, the currency would be cut off at the knees.