In my country since there are cases of bitcoin malware with the increasingly make bad bitcoin image in the eyes of the people.i Hope in your country is not so and hopefully the future of people's view about bitcoin getting better... 
People also used fiat currency for their criminal activities. So why now blame it on Bitcoin because is modern currency?
I agree, why blame bitcoin if people are the one who are using it. Bitcoin will be just an accessory to the crime.
Whatever people use for their bad doings it's not the fault of such thing instead the blame is all in the people.
And no one of us can prevent this because bitcoin is pseudonymous and no one can track transaction and we're all clueless.