That would make it profitable to become an outlaw miner who doesn't care where the transactions are coming from. Then they will outcompete the above-board miner

That would make it profitable to become an outlaw miner who doesn't care where the transactions are coming from. Then they will outcompete the above-board miners, because they will be able to spend more money to buy ASICs while remaining profitable, ensuring that control of the blockchain will be in the hands of criminals. The only way to prevent that is go nuclear and control the production and trade of silicon chips like we do with munitions. And even this is a very low-probability scenario. The most likely outcome is that the US and a few European countries try to do this, China laughs and does nothing, and Bitcoin belongs to China pretty soon (if it doesn't already).