I think you got it upside down.
Why would America subsidize corn if it can't be used to make anything? Its after we found out corn can be used in the production of other things that we started subsidizing. Otherwise why not subsidize broccoli?
I cant say I know the history of american corn subsudies but the story is usually along these lines:
america enters WWII and the people need cheap food for the war efford. corn can do that, its subsudised for human consumption and fed to the poor and the soldiers as well as the allies.
War is over, subsudies still go on because, hey.. theres still poor people.
Ranchers realize that they can actually feed that stuff to animals since its so cheap. That way, the meadows needed to keep a herd of cows is much smaller since you can now feed them corn.
some lobying work to keep the corn subsudies in a way that now include animal feed although that was not intended by the original bill. After all before there where subsudies for corn the idea to feed it to abimals was insane, just look at the price of the stuff. why would you feed mangos to animals. Or feed meat to fish, do you know how expensive that is (or rather...was. nowadays its done because subsudies make everything so cheap)
Chemical industry finds a cheap way to make mono-sacharides (sugar) from poly-sacharides (starch). Expensive sugar can be used less and cheap corn can be used instead. again, some lobbying to ensure that that is also included although the original bill was about having cheap food for the poor. Not making peanut butter with corn.
Chemical companies realize they can make petrol from corn. Again...
And so on, and so on. The fact that corn is subsudized made it possible that its cheaper to make sugar from corn instead of making sugar from cane sugar. And if you include the more and more expansive bill that the bill brings, its not really cheap. First it was to subsudize human food, then human and animal food, then human and animal food and various products of processed food, then all of before and petrol subsudies (indirect) and it will be more and more. Its your tax dollar that buys it and "makes it cheap", although... of course its not cheap but it seems cheap because you get taxed for your food and your petrol and your toothpaste with corn in it.
Perhaps, in the future they will find a way to make bricks from corn, or cement... or extract the iron out of it and make steel from it. As long as corn is so subsudized that its sold for less than it costs to make it, people will come up with new wonderful ways to use it. Other than eating the thing. Which was presumably intended in the original subsudization bill.
why not subsidize broccoli?
If they did that, then now there would be broccoli in every other product instead of corn. Take this threat:
http://www.historum.com/current-events/23666-balance-oil-power-could-shifting-soon-2.html
Edgewater argues that shell oil extraction is too expansive, and technology wont solve the problem. subsudies would. If you choose to subsudize shell oil extraction until its cheaper than regular oil extraction then people will start doing it and see it as a more profitable venture. It really is not, but who cares? theres subsudies. Making gas from corn? Who cares if its profitable... as long as there are subsudies all is well. If the subsudies wouldnt be there... who would care about the theoretical posibility to do it? its not paying so.
