Food production is a greater societal need and a lot of corn goes into making ethanol for cars to burn instead of food.

We don't have to outlaw ICE cars to make it more expensive to drive them, we just have to make corn ethanol more expensive for gas companies to cut their fuel with, and food corn cheaper for humans.

Also: We need to grow less corn overall. We make way, way more of it than we need and not enough of other better veg.