Usually when describing something in the face of scrutiny, one describes a use case. If someone questions the validity of hammers, the solution isn't to say "we call this a hammer." It's to show how hammers are used.
I doubt most crypto folks have any idea of credit markets or central banking. What they have expertise in is the manipulation of money. Bitcoin, and all of crypto, is Wall Street's love interest for a reason.
Bitcoin, with its Austrian hard money roots, stands head and shoulders above the crazy scammy mess of all the centralized altcoins (or "crypto" if you lile) that you right to criticize. Please don't lump real technological and computer science innovation in with a the crypto rug-pulls.
They think they have deep insights when saying "banks create money out of thin air", or "there is not enough money in the economy to pay down all debt". They also use the word "fiat" as if it's bad that a currency is backed by a government.
All the above are strong indication that there is something fundamental about the monetary system that someone fails to understand.
A lot of crypto has been bought because the buyer were under such illusions.