There is a 3-5% rate of people who don't enjoy music, and it at least doesn't obviously handicap them: https://en.m.wikipedia.org/wiki/Musical_anhedonia
There is actual evidence for my theory BTW. Aboriginal folks in Australia had a tradition of using songs to describe itineraries.
Antique poetry and the bits of oral traditions that survived until today were using heavily structured verses (like the dactylic hexameter). A notable exception is the old testament, whose first parts were transmitted orally before being written down, and which is structured in verses of unknown structure (or unstructured, except for the psalms).
Modern poetry has gradually lost that strong structure. The prevalence of musical anhedonia and amusia may very well have risen in recent times as a result of the loss of utility of music.
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We tend to make the mistake of assuming any seeming oddities of the human must somehow be due to evolution. But when we see the same in the rest of the body we often make the opposite assumption and assume it's a vestigial trait, or a coincidence.
Even if amusia (of which musical anhedonia is a subtype) was prevalent at the time, culture transmission operates at the group level. The mere existance of amusia with such a low prevalence doesn't invalidate my point.
Regardless, I don't think there's much evidence (if any) for the idea that the enjoyment of music is the result of a defect in our auditory system.
Defect would imply it's a negative trait. A lot of mental quirks are probably just irrelevant from an evolutionary point of view.
Not sure I've explained myself as well as I could, but hopefully I have.