People can use Bitcoin to take advantage of people since anyone can be anonymous, also no one has the full control over what you do. Government has the limited ways to regulate the activities being done.
Actually, criminals use Bitcoin because they misunderstand Bitcoin, they think that using Bitcoin is untraceable and anonymous.
Even though they forget to do cashout, usually if they want to make a withdrawal to become fiat they have to do the KYC procedure.
Because it is difficult to spend Bitcoin, they need a cashout to spend Bitcoin. Most criminals using Bitcoin are caught by the police,
because they end up using centralized exchanges, which requires KYC.
I agree, though Bitcoin allows you to be anonymous. A third party exchange to convert your coins to fiat will reveal an identity. But for sure since they are criminals, they can make a way to keep their self Anonymous. They have all the skills to take advantage of people and that ia undeniable.