Or we could blame the NSA for leaving these zero days in the wild and subsequent dump of said zero days by shadow brokers so any script kiddie can now deploy such things. We cant blame bitcoin. To quote Andreas Antonopoulos, " to blame bitcoin for these ransomware attacks is like blaming a dufflebag full of cash for a kidnapping". This will not kill bitcoin.
RE: The real casualty of the WannaCrypt cyberattacks is bitcoin