It's easy to blame "farmers" as a whole for some of the subsidies plus the use of plant based materials to make ethanol for motor fuel additive. The EPA wanted to go to E85 back when they first started to use more ethanol in the mix. They had to convince the world that man is indeed changing the climate. For every scientist that says man has a large effect on climate change, there is likely a scientist that can debunk the climate models they use to come to that conclusion.
The only "farmers" that have the money to lobby congress are the large corporate agricultural consortiums so don't blame all the mom and pop farmers for this stuff. They are at the mercy of the commodities market & middle men of the agribusiness system of the USA. If corn prices get too high it affects the price of beef, chicken, and pork as well. You can blame the government and the big corporations but don't throw small business farmers into that pile for they have very little sway in the matter.
The government should never have messed with food source materials to make non food materials if there are non food source materials that will do the same thing.
The next major discovery will be a way to contain and convert anti-matter into energy. Until man can figure that out, we are stuck with fossil fuels whether the government likes it or not.