I for example use a mixer because of when I use a service to buy Bitcoin instantly, I want my coins to be out of sight as the coins that I have bought have my details attached to it.
And that's exactly the reason for me to use a mixing service as bitmixer to get fresh coins that I can send to my cold storage, or to spend it somewhere.
Means bitcoin's transaction is not that anonymous as what other people think? Is it really possible to identify the dox of the user using his coin? How could it be?
The problem is this :
If I buy and withdraw coins from the exchanges where I am fully verified at with all my details, the coins that I send to my wallets will have my details attached to it.
From there the exchange can follow these coins and even find out to where I am sending them to.
That's not even the worst part, the worst part is that the exchange in question can play all this information to the government if they force the exchange to do so.