Naturally governments would call it laundering anyways, because governments do not like privacy.
Governments are not keen on Bitcoin as it offers people financial freedom by enabling them to store money outside the rotten banking system.
If they hate something for a certain reason, then this will be the exact reason. And in this case it's Bitcoin that receives all the blame.
Bitcoin mixers are used for mixing your addresses with some other so that no one know that these bitcoins came from your address and according to my views you can use bitcoin mixer in cases if you have some bitcoins in wallet which will be verifies and you want to use them in a place where you do not want to show your self and do not want to show to the wallet team that you are spending on that place.
Firstly, the coins are being mixed and not addresses. In reality you just receive new (fresh/clean) coins in return.
Your coins will at some point land into someone else's wallet as being their fresh coins.