It is possible to hire hitman to kill someone and pay them in bitcoin. It is possible for sick and deranged people to get illegal movies (you know the ones I am talking about) and it is possible to do all kinds of weird stuff with crypto. However that is not an issue on crypto, these troubles did not begin in 2008 all of a sudden. People did all of these things before crypto was a thing, it didn't became a problem now. People did this with dollars and euroes all along and it is a human problem, not a crypto one.
Well in truth it is not the fault of the technology if they are being used in the wrong things instead of them being used for the benefit of all. The blame should always be put to the people that used the technology for their own personal benefit and the people who believed them as if they will not believe them then people being scammed will lessen or cease to exist.