Bitcoin seems to be in another bubble, so I'm going to wade back into this insane discussion.
I agree that we're in a potential bubble, but bitcoin was never ever a pyramid scheme. Bitcoin is a fully transparent cryptocurrency system and investors were never promised anything.
Companies ought to have fundamental value (although one may be skeptical if a company has no plans to give investors access to that value via dividends or acquisition) but Bitcoin doesn't. Also, I think of Bitcoin as more of a bubble machine than a pyramid scheme.
I agree that we're in a potential bubble, but bitcoin was never ever a pyramid scheme. Bitcoin is a fully transparent cryptocurrency system and investors were never promised anything.