It is the same premise, because the person you are responding to is not talking about the moral implications at all, only about the financial / hardware implications.
Running AI inference increases the power draw, and requires certain hardware.
Mining bitcoin increases the power draw, and requires certain hardware.
OP's point thus stands: Bad players will find places to get far cheaper power than the intended audience, and will buy dedicated hardware, at which point the money you can earn to do this will soon drop below the costs for power (for folks like you and me).
Maybe that won't happen, but why won't that happen?