Nintendo was not pandering to the west with Off the Hook. You realize that there are multiple bands of different genres in the Splatoon universe, right? And it's not like Japan can't like rappers/DJs. Not to mention all the songs are gibberish and don't sound feel super dissimilar.
There is more to the splat fest hosts than just the music. Look at the whole picture.
No one cares about how Japanese the hosts feel (except you apparently).
A lot of people do actually. Most people I know are totally ok with Splatoon 2 having less of a Japenese feel. Of cause that's their opinion and they are entitled to it. My point is many people have noticed this difference. Some people like the shift in Splatoon 2, some people do not. Just differing opinions.
It's crazy to think a game isn't good because it's not "Japanese enough" when the only difference is a genre of music.
Firstly I didn't say the game was not good enough. I just said the new hosts totally changed how the game felt in many ways. I did say I didn't like the new hosts. That doesn't mean I think the game is bad. Splatoon 2 is a good game. I really liked it's single player modes and the multiplayer is fun too. The splatfest hosts themselves (ie not their music, I mean the characters themselves don't play that much of a role. You see them for a bit and then you are into matches or single player for hours on end).
Secondly, there's more to the hosts than just the music as mentioned above.
The Persona games also cycle through different genres as their main style for a game. And Persona 3 was even mostly rap. So it's not unrealistic to think that Japanese people might like different kinds of music instead of just the quirky pop you seem to think.
Persona is no different. Each game differes in many different ways. Music is only one of the ways each game differs. My opinion is Persona looks at what is considered modern culture, visually, musically and socially and blends that into a game. That's exactly why P4 is all about digital TV as that was the new thing back then and P5 is all about smart phones as everyone has one now. I'm very sure P3, P2 and P1 are just as rooted in the culture and society of the time they were developed as well.