Bitcoin mixers are basically the equivalent of money launderers. They are used to disguise the source of funds and are usually an attempt to hide criminal activities. If you use a mixing service, assume that you are sending money to scammers who will have no problem ripping you off.
Wow, that was harsh.
I have not committed any crime and I have been using Bitcoin mixers for several years now. I doubt that Bitcoin's pseudo anonymity is enough to protect you from good hackers and people who wants to steal your money. So you add a extra level of anonymity to protect yourself from these types of people.
A criminal will be stupid to think that they might use Bitcoin mixers to hide their criminal actions, because law enforcement agencies can subpoena these companies for this information and if they cannot provide the information, they can be prosecuted in future.
You have the right to protect your financial information from people, who wants to steal it. The banks does that for you, or so they say. If you use cash, you have even more anonymity than people who use Mixer services and that is why cash is still more popular than Bitcoin for criminals and money launderers to use.
