They don't understand stock to flow. I also used to think the whole thing was purely speculative, but there's rock solid logic as to why people see it eventually at much higher levels than we have now. 20k is set to be the bottom of the coming bull run, not the top of it.
People who tell you that Bitcoin is a scam/ponzy scheme in reference to fiat and the fractional reserve banking system as their "golden standard" of what isn't, risk making me cringe to death.