Bitcoin Mixers are not so effective as you may think. In fact it's not effective at all for people with ressources. Of course Mixers are not going to tell you this. Maybe for the average Joe but remember the blockchain is fully open. Using a Mixer you create a fingerprint and you can be traced (really). Another thing is you can be mixed with stolen coin, then I let you imagine what can be the next
Oh Please, How would you know if the coins you receive or even the
cash you receive was not involved in any crime? People come up with the stupidest arguments some time, and forget that cash is just as anonymous as Bitcoin. Bitcoin mixers just add some more anonymity to protect you. Imagine if all your cash transactions could be traced back to you or if people at a coffee shop could check your bank balance, once you bought something from them. That would have been possible, if you used Bitcoin without these mixer services. It is just a added layer of protection for the consumer. < Some criminals use it too, just like the Internet >