Criminal RICO was intended to take down a crime syndicate by locking up all of its members. Civil RICO was intended to take away their ill-gotten gains. But RICO actions are complex and costly, and the mob has deep pockets. Criminal defense attorneys are part of their overhead built into their business model. So it’s much easier to do a civil RICO action against the small time operator, and clean him out. He can’t defend against it. Since the predicate crimes that trigger a RICO charge constitute practically the entire criminal code, and in the civil RICO actions the standard of proof is only preponderance of evidence, it becomes an easy money deal for the government.
I saw a civil case out of the 6th Circuit recently where the court let stand a RICO suit against an insurance company and its salesmen for peddling a tax shelter for the wealthy the IRS ultimately ruled did not work. Sure, they owed some damages, but that was hardly criminal conduct.