The US is a huge country (9,833,520 square kilometers!), so I find it curious that such generalization can be made about the food available here, or even the eating habits of 334,914,895 humans. I could say that I visited Amsterdam 2 years ago and I was shocked with the quality of the food.
But I would never do that, since I mostly ate at the Red Light District, and I couldn't possibly generalize the country eating habits with stores in a major tourist area.