Uhh no you would be completely wrong. I only need one scenario where it is useful. You have it backwards.
If I'm a criminal and I find a flaw in the legal system, do you think I would still go the obvious way and get caught? Once there's a flaw, everyone will start to use it and the system is just a big curtain. Unless the flaw can be fixed (and there's no way to fix coin mixing as far as I'm aware), then all effort is futile.
I didn't say what i want is a solution, it is simply a way to do some basic due dilligence.