Evolution doesn’t tend to result in nice simple structures, to be honest. It’s a mess of interactions between repurposed systems. We’ve not even begun to address the importance of affect in cognition, for example. It’s pretty much impossible to separate out affect (ie mood) from cognition in practice. That points to the origins of cognition as a coordination process for achieving embodied needs. Trying to build a human-like system of intelligence without including moods and emotions thus really misses a major part of what cognition is.