It's all about balance of flavors in the end. Spicy, Salty, Sweet, Sour, Bitter, Umame (I count spicy as a flavor, even though it "technically" is not). All of these additions are just tools to get your chili to trigger on all cylinders is all. For a mild, thin chili, I could understand being leery about adding such things as they would obviosly stand out. But in a well made red chili, with a flavorful meaty gravy and a good strong flavor of chiles and some onion to boot, then you are not going to notice the unique flavors of these items so much as the subtleties these things introduce (unless you add too much of them of course).
