The problem with Marks analogy is when applied to the U.S. Dollar, you obtain the same result since there is absolutely nothing backing the U.S. Dollar. From my point of view, crypto's have the same value as any Fiat currency (whatever the market is willing to value them at). And to call a blockchain Crypto-currency a pyramid scheme tells me he need a good dictionary to get a proper definition of pyramid scheme!

Just my 2 cents

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