Sometimes it's more of a "taste" or perception thing. Once people take a negative view of a particular food, they tend to keep that view no matter how good the food really is.
Take "Spam," for example. Spam has a bad reputation, yet it's not a bad food (or else it wouldn't be sold all these years later). It's ham and pork shoulder. However, Spam or that type of canned meat was a common staple in WWII GI food packs. After eating that for years during the war, the GIs that returned home shunned it in favor of other foods. The reputation grew despite the quality of the product.