Well, culture is much more than language this song is written at, there is still alot to different cultures in the show embedded in those songs and performers...and still it's part of creating shared Big World of cultures, having common language is helpful too.
I listened to the songs that were in foreign languages and (beside romantic-sounding french (aka "langauge of love"
) or italian that are nice even without understanding words), it's quite boring and frustrating to listen to song (in most languages) you don't understand lyrics from. I was sitting frustrated at those songs, I do prefer english and wished more songs had more in english. Lyrics is big part of a song.
...Or in russian, at least a language I can understand lyrics from
Not all languages sound equally appealing too.