There are many way to do money laundering. Even if those hackers use worthless new coin but they agree with the value of it then it is works. Law enforcement should focus on the hackers. I think even if bitcoin is not exist those hackers will still have desire to hack to get money. The problem is the human not bitcoin. I am pretty surprised that some people has that way of thinking.
Fraudulent and illicit activities are happening since centuries and will continue in days to come, there is no way to eliminate them. Government can play its role to minimize them. Hacking was there even before BTC came into existence. Technology is double edge sword and it has both good and bad usages. AFAIK, government just using such issue to do more opposition to crypto rather then targeting the real issue.