If labeling was required, there would be a split stream in this country as well. This country already handles the products in a split stream, for exports. They just don't want to acknowledge it, because it would show just how easy it is to separate the products, and label them separately.
I agree that the labeling could be as simple as "may contain GMO corn or GMO soy", just like the allergen labels. The industry circumvented labeling because of consumer squeamishness, and continue to lobby against labeling for the same reason. American consumers like being blissfully ignorant, as many people have mentioned here. But they also want that choice. It is the difference between an opt-in and and opt-out. The current system is an opt-out, you are in the GMO product line unless you spend a great deal of effort to avoid GMO products. A labeling system gives you an opt-in, and makes for more informed consumers. I have to buy organic cornmeal at the moment to be sure the cornbread I make at home is not GMO. It should be easier, and I as a consumer, should have a choice.