Ransomware is natural evolution of cyber crime, it is not because bitcoin was invented we have this problem - it is the the other way around.
Blaming BTC for ransomware is like blaming RSA encryption schemes or any other encryption method - because thanks to them our files can be targeted...
Cryptocurrency is a just a catalyst for every cyber crime but it is too late to back off, if not BTC they would be using LTC, ETH, XMR or Dash - it doesn't matter.
Scare tactics and economic propaganda seem to be working as these misconceptions are still pervasive - even within the crypto community it seems.
If you think about it, BTC is actually NOT an excellent tool for doing stuff online - not when you have to go through the trouble of washing your bits a billion times (and believe me, the most dogged Tom, Dick or Harry can still trace back your bitcoins).
Doing fiat with corrupt bank officials is still the choiciest and easiest way for criminal activity. You can't "fix" the blockchain.
You are talking about big time criminals, for example, illegal arms merchants or human trafficking operators. And I suspect that the latter are not very interested in doing stuff online altogether, they are more "mundane" in this respect. Smaller fish like scammers, fraudsters and darkmarket users whose illegal activities are conducted mainly through Internet might not have such option readily available to them. And this is where Bitcoin gets quite handy...