What the parent is trying to argue is that the entire idea of money laundering should be forgotten and there should be no negative public perception of money laundering. What I'm arguing is sure, maybe people shouldn't go to jail for money laundering by itself, but there are zero legitimate reasons to launder money. The very fact that someone has gone to any length to hide the source of their income means they've committed a crime. Not the crime of money laundering, but the crime of whatever they did to earn the money. Because if they didn't commit a crime to earn it, they wouldn't go through the trouble of hiding it. Money laundering is probable cause for further investigation.

His argument sounds to me like people who argue that since the Constitution doesn't say the government can collect taxes, that means taxation is theft and we shouldn't pay them. It's the libertarian ideal that money is private property, humans are inherently good (unless they've won an election), and laws don't apply to you if you just believe it hard enough. Unfortunately that's not the way the world works. In reality, where there is smoke there is fire, and where there is money laundering there is someone concealing a crime.