There is no law that prevents 51% of the node operators from forking the Bitcoin code. Even if there was, scarcity isn't the same thing as value. My kids art work is incredibly scarce compared to Bitcoin. I can copyright it so that no one can copy the only original that I own. But that doesn't mean it is going to go up in value.
Bitcoin on the other hand is a finite resource. It stops at 21 million. It can never go higher than that. New shitcoins are birthed everyday, but they are not Bitcoin.