Why the downvotes ? It's actually true and really relevant to the article. Music was way more localized back then and a lot of mainstream US artists never actually reached a worldwide audience. (especially on the Rap section of the article).
While I don't doubt your mental narrative nor dismiss the value of evidence, if you think about the parent's assertion ("US and pop-culture bias") longer, it's obviously correct.
I agree with the parent poster that the article is US pop-culture centric. I just wanted to point out that the data isn't, necessarily, strictly US specific. I also felt that that the parent comment was a bit snarky given that this website has a large US audience, and US music and pop-culture are popular around the world.
In which case, I should voice my opposition to the suggestion that we non-USians (eg. I'm an Australian in China) should communicate (even in our own language) with hat tipped to US popular culture because (inertia of Colosseum-fawning masses).
Here's a contrary view: I believe that intelligent people tend to respect and encourage diversity because it's both more interesting for them ("are we nought but latter-day curios for the coming AI overlord?") and because many fields of science (chiefly biology) show us strength in heterogeneity. The parent's comment was, I believe, offered in this spirit.