This is not a failure of bitcoin. Suppose you had a stack of companies whose purpose is to store your physical gold and prevent it from being stolen and to serve as an exchange allowing customers to trade gold for currency. Then, it turns out that some of them had inadequate security or were outright crooked and the gold they were storing went missing. This would not be a failure of gold itself. Sure, if sufficient quantities of gold were affected, it would affect the price of gold, but it does not change gold itself. This is the same situation.
The real problem here is the notion that bitcoin is a currency. It really isn't. It's a virtual commodity much like gold, with similar properties save for the fact that gold is physical and bitcoin is not. (Sure, the odds that everyone suddenly decides to pack up their toys and ignore bitcoin are much higher, mostly because there are no "real" uses to bitcoin, unlike gold which has actual uses other than being somewhat "rare" and looking pretty.) The same things that make gold less than idea as an actual currency (or a backer to a currency) apply to bitcoin. Sure, you can use either one as a place holder in a transaction if both parties agree, but you could just as easily use a common fiat currency, chickens, or grains of sand.