If you were in my shoe, what would you've told a person that says bitcoin is a ponzi scheme created to scam people?
Tell them that Bitcoin is
Digital Socialism.That usually stops 'em in their tracks.
Tell that to a socialist or leftist thinking and I think it will not stop them and they would rather continue researching what this is and possibly participate. So I really don't think by saying that would stop them from doing crypto but rather it will do the opposite. But if you are going to ask me, decentralization which is a feature of Bitcoin, would shy those who are diehard leftists since they are for the centralization of government - their government and in a socialist utopia, they don't want a currency that cannot be controlled for the benefit of the masses or the socialist government - again their government.