In nature, sweet things are very rare, and in their natural state, most things that we buy as sweet aren't really so much. Many fruits are sweet, but also tart, and many other plants have a hint of sweetness. The only substance I can think of, right off the top of my head, that is truly sweet, without any help from humans, is honey, but to get to that honey can be necessarily painful, and maybe a little dangerous. As such, it is a very precious and highly desirable substance.
Sweet things are rare, but the other very interesting thing about sweet stuff in nature is that it's not poisonous. So, if you come across a plant, and it has a sweet flavor, it's not going to kill you.
The result is that we are genetically programmed to prefer sweet stuff, because in a world in which people live *with* nature (as opposed to one in which we try to control nature), those sweet things will not be deadly.
Perhaps this is intuitive knowledge, and we know it, but on a kind of unconscious level without ever really thinking about it. I'd observed the phenomenon in my children, who always preferred the fruit-based baby foods (banana was a favorite) to the less sweet vegetable-based baby foods (although sweet potato and carrots, which are made sweeter with cooking, were also favorites), but I never really thought much about why. As a personal preference, while I like sweet-flavored things occasionally (and I love combining flavors and textures - like salty, crunchy peanuts with smooth, creamy ice cream), mostly if I have a choice, I'll go for salty, but I think that my personal tastes are not usual. Most people prefer sweet.
Perhaps food manufacturers just observed through trial-and-error that sweet stuff sells better.
Or perhaps food scientists actually studied the phenomenon and have been manipulating processed foods for the better part of the last century by adding sweetners to make the food more appealing to our human palates.
Whether it's an insidious plot or a concidental occurence, the fact is that sugar or some other highly processed sweetner is added to nearly everything that one buys in the stores these days. Check out the labels - corn syrup, high fructose corn syrup, or sugar is in just about everything: chicken sausage, tomato sauce, flavored corn chips, and bread all have added sugar - and those are foods that aren't, necessarily, supposed to be sweet.
What makes the whole thing so stomach-wrenching, to me anyway, is the fact that food manufacturers are now making *sugar* out of things that should not be sugar. Most of the white sugar in this country is made from GMO sugar beets, and most of us know we should be avoiding high fructose corn syrup, which is a highly processed sweetner usually made from GMO corn.
As a culture, we have, perhaps, been conditioned to like life a bit sweeter, but perferring a sweet nectar to a bitter pill is more biological than cultural.
It's just a sad reality of our society that someone discovered a way to get rich off of a biological fact.
I wonder if we'll ever stop allowing ourselves to be manipulated by those who only wish to profit from our humanness ....