Look at the money trail, ethanol is the poster boy for campaign finance reform. ADM - and others -have given many millions to advance its business, basically using government subsidy's, the gas tax avoidance provisions, etc for their personal gain.
I am not sure I know of any environmental group that thinks taking a bushel of corn.....500,000 btu's of energy....adding 150,000 btu's of processing and distillation energy..... then getting about 150,000 btu's of ethanol out..... to be a good deal.
What you really hear is some big business's saying its good for the environment, not environmentalists.
Sort of like the "Clean Air Coalition". which is all funded by coal companies.
Burning corn in a corn stove or for power is simple and gives a much higher energy return, it just lacks well lobbied federal tax subsidies!