There are coins out there with a fixed supply of only 4 coins. I don't hear you rallying for them merely because of their "scarcer" supply.

Value is subjective (you would think this would be obvious to an ostensibly austrian econ crowd) and a function of demand. Demand is always changing. You can't fix demand.

https://github.com/libbitcoin/libbitcoin-system/wiki/Scarcity-Fallacy