Real talk time:
Despite not being a very patriotic country like 'Murica is, Japan has a tendency to look down on other people as inferior, especially when it comes to their own culture. (Hence why characters like Tonio have disgustingly bad accents, to make it clear that foreigners could never master the nuances of Japanese the way a Japanese person could. Or why when Joseph buys kebabs from Steely Dan, the narrator says "the logic of the West… and Japan doesn't apply".) There have been a lot of controversies recently over how half-Japanese people should be seen in society, like when that half-African American woman won a beauty pageant. Araki himself said that making the first protagonist of JoJo English and not Japanese was very controversial at the time. And sure, nowadays there are a lot more "foreign" main characters, but not really since they're usually either A: supernatural, like witches or succubi, B: from some pseudo-European country, like what they do in Strike Witches or Izetta or C: both. Rarely are they real people from real places with a real grasp on the culture.

On the other hand, Jolyne is female, yet not at all the standard sex object found in most shonen manga and Part 6 takes place entirely in America. Of course it's not popular over there. How many ten year old Japanese kids care or know about the KKK or black identity in America? Likewise, how many ten year old American kids care or know about the Black Dragon Society or Ainu people? But Araki still went with it anyways, nearly causing JoJo to be cancelled as a result… until he switched to the older men's magazine, Ultra Jump, not because JoJo was getting too violent, it was actually getting less, but because it was getting more mature, thematically. That's what I love about Araki, he's unwilling to compromise his artistic vision just to fit the traditional paradigms of his nation. That's what I think of when I see this image, because for Araki to prefer Western music to Japan's own and say it on some talk show probably takes a fair amount of courage. I respect that.
Real talk time over.