Cash can be used for illicit activities. So can the internet. So can mobile phones. So can cars. Why don't we rally against all these things too? There is a massive difference between a legitimate service which is used by some for illicit activities (such as a mixer), and a service which is by its very nature illicit (such as a Ponzi or other HYIP scam).

Similarly, this argument is complete nonsense. Buying groceries and human trafficking are both part of the cash ecosystem. Does that make them equal? Such a comparison is meaningless.

Scams are not moderated, so they are unlikely to make a decision. Stop looking for an excuse you can use to justify promoting a scam. No one else can change your signature for you - this is your responsibility.