It is in quotes because it conforms to some definition of "correct", which is rather ambiguous, and because hue isn't the only factor of complementary colors.
> While useful, it's clear that our understanding is very limited.
I respectfully disagree. (Though acknowledge that our understanding of color is not complete.) I assert that our understanding of the mathematics of harmonious color are well understood because the spectral relationships are fairly straightforward. It's not uniform, like auditory relationships, but at least narrow-frequency relationships follow pretty simple patterns once the perceptual space is compressed. (Thus 180 degrees being "correct" complementary.)
The problem arises in our computationally-efficient matrices/transfer functions which distort those relationships and introduce the lightness and chromacity. I acknowledge, however, that it's not quite as "firm" as I phrased it.
> ...the only reasonable way to teach people how to pick harmonious colors is to have real humans use their brains and sense of aesthetics.
I agree that it's way better than shifting an HSL/HSV hue 180 (or however many) degrees to find a harmonious color. It's way more complex than that, and a proper tutor is much more valuable than an erroneous color space representation.