Corn vs sugar doesn't matter. It's all the other steps that make ethanol not worth it. I should have said sugar in my comment to be accurate to the article, but by far most ethanol is made from corn due to US corn subsidies which is why I mentioend corn.
It really does. Corn ethanol takes a unit of fossil fuel to produce 1.3 units of ethanol, while sugar cane produces 9 units of ethanol for the same single unit of fossil fuel. I'm not sure what happened to switchgrass, but it's reportedly twice as efficient at producing ethanol as sugar cane, 20:1.
Ethanol isn't a terrible idea, depending on its source (corn is bad, while sugar cane, sugar beets and switchgrass are good). The infrastructure is already in place, takes little cost or effort to convert a petrol vehicle to ethanol, and ethanol provides better performance in ICE vehicles than petroleum, though at the cost of slightly less milage. I think losing a little milage is a small price to pay for better performance, clean air, and no contribution to Climate Change.
Makes me wonder if your comment is literal copypasta, or merely figurative copypasta from US ecoactivism.