We all know that snake oilers can be very convincing and use rhetorical tactics that many well-meaning customers cannot cope with. Once you have accepted their arguments, it is difficult for third parties to penetrate this indoctrination with real facts. Often the victims have also turned themselves into perpetrators by recommending or even sub-selling these products to others. Then it is no longer about facts, but about personal honor. Nobody wants to publicly admit that they have been spreading complete nonsense for years, so that miracle cable sellers could enrich themselves at the expense of gullible people.
I see this behavior again and again, whether it is with people who believe in alternative practitioners, stone pendulums, but also useless petrol and oil additives, miracle spark plugs or earth wave protection devices. Just to list a few of them. People even put their life into the hands of such crooks, ignoring modern medicine.