Its a peer-to-peer digital cash system.
...that you can use in a peer-to-peer manner as well, without having to interact with a third-party. Craigslist exists and that's a proof face-to-face txs aren't "a mistake". The difference is, after you meet someone f2f and they hand you a $100 bill, you cannot check its entire history from the moment it's been printed. This is where mixers come in as handy.
What is your position about cash? Do you like it, or would you rather be a bank's slave and declare where your money comes from, where it goes and what kind of toilet paper you like?
Then proof the exchange that the coins your owning are not from criminal origin and your good to go.
Why accuse me of crimes when I ain't a criminal? Why should I prove something you
suppose is coming from an illicit source? Why do you even care as a company about my finance?
And then, there are companies abusing KYC to steal. Freewallet does that. And Bittrex. And many more.