Bitcoin has nothing to do with increase in criminality rate.Criminality was there even before bitcoin was created.It would exist even if bitcoin dies.Criminals would love to use coins like monero ,zcash which are fully anonymous and not bitcoin which is pseudo anonymous.
I would like to disagree. Since bitcoin is one of the leading crypto-currency in the market with a significant amount of fiat if converted to, it has been used as a gateway of criminals for illegal activities due to the identity of the accounts being unknown. Its characteristics also of being unable to track and the lack of government intervention results to criminal activities. Just to give you an example, there have been several cases on illegal transaction involving bitcoin - an example would be the notorious cases of silk road drugs and mt. Gox.