To phrase it another way: practicing scales can be boring. But playing a walking bassline is a whole lot more similar to scales than it is anything else, and one of the most fun things to do with an instrument is to jam with other people using the fundamentals you all share.
I never felt the same way with math, because I never felt like math allowed me to put anything unique and of my own into the mix. Learning the same proof from a book that a million other kids taking geometry learned was much less interesting to me than transcribing a solo some musician played so that I could try to riff on the style they put into the world.
Sure, yeah, there's rules in music theory too. You're expected to learn them, and get graded on them in tests if you study music academically. But I don't know of any famous mathematician who ever said something like the various Duke Ellington quotes around "if it sounds good, it IS good". In the art world, similar riffs on an existing idea are everything. In math, they're just... wrong. Or at least thats the understanding I had as a student which led me to only care about the parts of math that seemed to be directly applicable to me, or really intuitive.