Ben H. your reasoning seems a bit simplistic. And your bias for your own product may be showing a bit.
Some believe ag subsidies are more about keeping food costs to consumers low as possible......and no denying, with food costs STILL in the 10% of income range, they are low and allow people to buy luxuries they could not have if paying comparable to many nations for their food.
Cattle were quite a bit different back when feeding corn began, including much older when first sold, often at age two to four years or even older. Not many years ago, "grass fat beef" was probably a critter more than four years of age, brought in off the range in the fall and processed. Most likely it didn't turn many people on to grass fat beef. That beef probably needed some corn to improve eating qualities, as do many current breeds/grades of cattle.
There is the fact that many consumers have come to prefer the flavor of corn fed beef. Now, some like the flavor of grass fed, and others like the novelty or 'green' reasons for eating grass fed beef.
It is good that there are getting to be many types of beef to suit various tastes of consumers and even the life-style or 'feelings' of the consumer. It seems unnecessary to knock other styles/preferences to promote ones own product, IMO.
mrj