Bear in mind that "sugar" in the US is generally not actually sugar but High Fructose Corn Syrup, which tastes almost (but not quite) as bad as artificial sweeteners, and has been linked to increased obesity rate far more strongly than cane- or beet sugar.
Between huge tariffs on imported sugar (intended to protect the two guys in Florida who grow sugar cane domestically), and the subsidy on corn, HFCS becomes much cheaper than sugar, despite being far more labour-intensive.
This is what happens when you let politics get in the way of deliciousness.
For similar thoughts about trans-fats,
see here.