Mixing tainted coins with other tainted coins will still be useful for criminals who want to hide the origin of their money. Without mixing, a prosecutor may be

Mixing tainted coins with other tainted coins will still be useful for criminals who want to hide the origin of their money. Without mixing, a prosecutor may be able to link the coins to a specific crime. I mean, let's not pretend that output from Bitcoin mixers ever was "clean money" in the first place. If you buy a house or whatever, the government is going to ask where you got the money, and they're not going to be satisfied with "You'll never find out, because I used a 100% legal Bitcoin mixer to hide the origin of my money".