The reason I make the claim that it is unlikely any human categorically dislikes music of all kinds is because what we can consider music is incredibly broad. It is like making the claim that there are humans who don't enjoy art. It seems nearly impossible because the nature of art is such that it permeates all human endeavor. Medicine, for example, is art. Lots of science in there of course. But there is a lot of art as well. I don't mean "an art" either, I mean art. When people start doing things creatively according to their internal sense of aesthetics, they've made some art.
"I don't enjoy music" meaning "I don't pursue even a tiny interest in music" seems plausible to me. What seems implausible to me is the statement "I have never enjoyed a work of music in my life". I'll admit that it isn't really based on anything I know about cognitive science, so I could be wrong. There might well be people who actually don't like any combination of melody, beat, rhythm, or whatever. The reason I find it diffiult to believe is because music is just artistic expression, and artistic expression seems to be a part of what it is to be human. I would think that some form of music would resonante with anyone because by the definition of art there are nearly no limits to what one could consider music. If there was no music a person liked, I would think they could make some by just tapping their fingers on a table in a way they find calming/pleasing/whatever.
All the crap I just said in this post is unrelated to my training as a linguist. Like I said above, music doesn't preceed language, and linguists have no need to study it as a foundational sort of thing. I also happen to have a philosohpy degree, so the above is mostly me trying to make clear what we mean by our terms.