Banks have deposit insurance because they operate under the fractional reserve system and loan out almost all of their deposits, putting them at risk of failing and losing all your money. Hence FDIC and whatnot.
The bitcoin network doesn't do that, hence no need for FDIC. The apparent risks to the BTC network are that a malicious entity gains control of > 50% of the network's computing power and uses that to illegally modify the blockchain, or the network goes down. The network is so big now that only the largest botnets would have a hope of the former, and it would take a global calamity like a scorched earth world war, asteroid, or EMP from an intense solar flare to accomplish the latter.
