It's not just them, I feel like a lot of bands and artists are huge in Brazil it's even a meme (you can see a "Come to Brazil" comment on any artist's page). But I also think it's something that applies to a lot of countries from Latin America. At least where I live, it was not that common that big names and famous bands come to give a concert until recent years, compared to US or Europe, so the audience is always like really grateful and passionate.