This is such an off-base critique that it seems like deliberate trolling. The biofuel renewable carbon cycle takes carbon from the air, and burns the carbon once it's in the form of ethanol. It stops taking carbon from the ground and putting it into the sky.

The problem in corn's case, the reason none of this works, is you need to burn lots of fuel to produce corn. LOTS of fuel. Enough that you could barely (in some studies) or not even (in others) produce more fuel than you burned.

If you electrify your farming you don't have this problem. A far-future use-case is that we have eliminated 95% of fossil fuel use, and use solar-battery-powered tractors, trucks, and combines to harvest biofuels in order to fuel long-haul aviation and certain other legacy hardware that proved difficult to electrify.