His argument seems to say that the LIQUID supply of bitcoins is shrinking because people are hoarding them. You can make the same argument for stocks or anythin

His argument seems to say that the LIQUID supply of bitcoins is shrinking because people are hoarding them. You can make the same argument for stocks or anything else that is traded for cash, but it's wrong. Everybody will have a price that they're willing to sell at - it's the fundamental idea underlying every exchange market.