Simply not true. I can agree to an extent that governments don't want you to use such tools, but it's plain dumb to believe you're being more spied when using them than otherwise. I agree you're a probable suspect for some, but you're a suspect for a reason; you do gain privacy. If I was being monitored more effectively, I wouldn't be a suspect. I am, because they very much work.
I took my time to think deeply about the mixing, money laundry, and the crime that could be committed via it but I realize that there is nothing different from what has been committed with fiat. The government knows too much about us, companies know too much about and these people are using their positions to sell our data and track us, this is from the fact that anyone could send assassins and thieves to you when they know what you are worth, getting your privacy through mixer is not a crime.
Let the crime be left for our individual action, no government, organization, or persons can claim that they are 100% clean even when they pretend to be. That is how I see mixers too, it's what we use them for that can judge us, and nothing has that power and integrity to completely condemn it.
By law, it is never illegal, what is the headache?