For starters, the tax applies to all other vehicle fuel, not paid by just a couple drivers on the road.
Fine. If it'll make you happy, let's say the bully steals lunch money from EVERY kid in the fourth grade except his friends. He doesn't give them any money; he just doesn't take it from them.
So, are you really going to say the bully is subsidizing his friends' lunches because he takes everyone else's lunch money?