I'm not a biology person at all so please forgive me if my question is silly. I was just wondering that why didn't evolution cause us to digest, without issues decomposed food?
Food is considered "rotten" when it has a large population of micororganisms like bacteria and fungus eating it. Some of these microorganisms have evolved to produce toxins that harm animals that would otherwise eat the food. Animals could evolve to tolerate these toxins, and some have. However, bacteria have a large advantage over animals in an evolutionary arms race due to their short generation time and large population number. So competing with bacteria over carrion is a specialized niche, avoiding it has been selected for in most animal lineages.