The judgement of the majority is not always reasonable. What he is saying is whether he thinks that the current pricing is reasonable.
Yet, democracy is based upon it.
No. Democracy is based on the notion that the judgement of the majority is reasonable the majority of the time, not that it's always right. In fact, one could argue that it's not even based on
that notion, rather just the notion that changing governments on a regular basis and having checks and balances on a government helps to prevent a dictatorship from forming.
If people are willing to put their money up then we have to accept it.
So in a democracy, does someone with 1000 times more money than another person have 1000 times more votes? No, because BTC isn't a democracy and we don't know how many people agree with what price.
Why bother speculating about consensus when you can just make actual arguments? It's that sort of
argumentum ad populum that takes over every YouTube comment section and renders huge swathes of the Internet worthless.
To me the value of diamonds is unreasonable.
Well according to you, it's unreasonable for you to say that. After all, people put up their money, so you have to trust them right?