<snip>But then again I've lost track of the numbers of times I've heard the comment "all Latin music sounds the same", which is as dumb a comment as all European music sounds the same. Just because someone cannot tell the difference between audio gear or different Latin songs [or whatever] does not mean there is no difference. Are you sure that you are interpreting that comment like it was meant to be?
If someone told me that "all country music sounds the same", I would interpret it as the variation was so low that one song had the same value as another for a particular listener (meant as a negative remark towards one genre). If the statement was supposed to be "no-one will ever be able to distinguish song A from song B in a blind listening test", that is indeed a strange comment, and one that should be easy to disprove.
What people mean is quite simple - they
cannot tell the difference. No more, no less.
But they usually say so as if it were the music were to blame and not as it is usually the case that they are simply unfamiliar with it.
A chap I know who played in a Latin band admitted that when he first came to salsa classes, he couldn't tell the difference between a salsa track and a merengue track - salsa + merengue being two very different dance styles, done to quite differently structured music with very different tempos. And no chance with differentiating between a son and a cumbia [two examples of many kinds of music that you can dance salsa too]. The reason, despite being a musician, he was completely unfamiliar with Latin music.
If people are familiar with something be it a musical style, a language or even a fashion style, they notice the differences. However if are not familiar what they notice are the similarities. But people very very rarely acknowledge this basic human attribute and normally blame whatever it is that they are not familiar with.
This is why people always moan that the music they don't like is boring and repetitive, despite the fact it is probably no more repetitive than whatever music they like. The important difference being you don't mind sounds you like being repeated.
As for blind listening, do you think you could tell the difference between someone speaking Hokkien, Cantonese and Mandarin or would it simply sound like Chinese to your ears [assuming you are not familiar with these languages]? And what about accents? Could you then tell the difference between people who spoke Hokkien but were from different parts of the country and who had regional accents. All things very easily done by native speakers, but exceptionally difficult to those unfamiliar to a language. An English speaking French person, who has not spent a long time in the UK, would struggle to place UK regional accents and they are markedly different as some of them are based on languages quite distinct from English. Yet [when I still lived in Wales] I could tell what specific town in Wales someone lived, by the different type of Welsh accent they had. Heck accents can vary from one village to the next here in the UK.