Simple really, most people don't actually know what a Ponzi scheme is nor what qualifies something as a Ponzi. Bitcoin is not remotely a Ponzi scheme so you can

Simple really, most people don't actually know what a Ponzi scheme is nor what qualifies something as a Ponzi. Bitcoin is not remotely a Ponzi scheme so you can immediately tell those who claim it as as someone without the faintest clue as to what they're talking about.