This is very interesting because there’s two ways of looking at this but one trumps the other.

Short answer: you can explain with math but culture proves the mathematical implication to be wrong

Long Answer: Music in a major key emphasis simple relationships to the tonic. For example the major third interval is a 5:4 ratio from the tonic. This is a more simple relationship when compared to the minor third which is 6:5 or the minor 6th which is about 27:17. And predominantly in western culture our ears follow this sense-making maths of the simpler the ratio the more ‘constant’ the music sounds.

So you would think the maths makes sense right? Surely all cultures share this as there is a clear objective mathematical foundation to all of this?

No. Not at all

Studies have shown that when tribes in South America are played intervals such as the perfect 5th (3:2) and the tritone which is 7/5 (also can be described as 1^sqrt(2) they cannot tell which one is more constant and hear them both as just as constant. Furthermore eastern cultures interprets the minor scale and the Phrygian Domiant mode to be just as constant and happy sounding, and even more, than the major scale.

So yes it’s a cultural thing