If he wants to argue that Bitcoin is a pyramid game, that's a different argument, but I can't see many people taking him seriously.
Pieter's arguments are along the lines of a "Think of the Children"[1] style argument, or an appeal to consequences[2].
"We must ban cryptocurrency because if we don't, people might lose their money!"
I mean, I think that Jack Dorsey is banking hard on bitcoin because he knows he's near the top of the pyramid and he wants as many fools as possible beneath him, but there's absolutely no way to prove that he's not just a soft idiot.
Just guessing though, all I mean is "if we don't, people might lose their money!" would have applied to Bernie Madoff too.
Make the ponzi/pyramid scheme case from top to bottom and educate people if you cannot make a case for illegal practice.
I think your only argument holds, slightly, if by "real value" you mean "money".
This is the opinion of the CPB director in a letter, so it's not binding in any way.
> A cryptocurrency crash is inevitable, he says. That is why the Netherlands must intervene.
Should the government be banning any speculative investment that appears to be in a bubble?