Ethereum also has to survive the inevitable bugs in the EVM (Ethereum Virtual Machine ) and user written contracts. When those contracts start becoming real with actual value attached and popular enough that it's worth spending time to analyze you're going to see every hacker in the world trying to exploit those contracts.  So the real test is can Ethereum survive a confidence loss when the media is running multiple headlines about money disappearing because somebody analyzed a SolC control flow graph using satisfiability and discovered a way to steal millions of dollars.