I agree with your points, and carbon benefit is not my only consideration either. Biofuels may prove dirtier than fossil, in the long run. I haven't worked out all the numbers, but I strongly suspect fermentation fuels may wind up consuming more energy in their production than they will yield when burned. Even if that statement is exaggerated, the start-up cost in dollars and energy will be substantial.

The energy budget is complex and interconnected, and dominated by existing and potential stakeholders who seek financial and political benefit at the chokepoints they control with little consideration for the big picture. This is not an Us vs Them issue, it's more of an everyman-for-himself-and screw-the-rest issue.

Even my pet project, fermentation of agricultural wastes, has only been proven feasible with sugar cane.