Unfortunately, their definition of "money laundering" is extremely broad and encompasses any means and technologies used to obscure the criminal origin of money.

If you acquired gold on black market with "criminal money", then re-melted that gold into new, untraceable bars, sold that gold on a "legit" market, that would be money laundering, even though gold is not considered money.

Bitcoin and mixers is no different.

Not that I agree with this. Prosecute the man, not the property.