Yes, but what defines a pyramid scheme is its unsustainability from a mathematical standpoint, not necessarily the fact that original owners and early adopters make money off of new investors. I think the latter property is present in almost all financial markets -- the "smart money" phenomenon.
I agree that the entire cryptocurrency market is in a bit of a bubble, but to write it all off as a pyramid scheme seems a bit of stretch to me.
edit: also, "pyramid scheme" to me is a very loaded term with a specific legal meaning to it as it applies to one single entity, i.e. the person or company operating at the "top" of the pyramid. There isn't really such an entity at the top of the entire cryptocurrency market, so I think it's much more apt to call it an asset or asset class bubble rather than toss around such contentious terms.