I would agree with everyone in the thread that yes, electronic and Japanese style music present a less difficult time for mapping, when considering some of the bigger well known mappers. Also yes, the game itself is centered around on a anime/Japanese style. I mean, the default skin of osu! has an anime girl pop out on combo burts but lets put that aside. The community is based around people who like and enjoy this culture, so in turn those maps and songs that swing to this culture will get more attention, and in some cases become ranked as well. Believe it or not, osu! does have its fair share of western music maps or as put "normal" by the OP. The trade off is new or inexperienced mappers. It may be pending or even a map in graveyard. Then put all of this aside. Osu! is a rythm game, you play and you have fun doing it and listening to what you desire. Just cause a map is a little bit slow or not mapped that well, doesn't mean you can't play it. Just because it's not a popular Sotarks map that is an anime opening, doesn't mean it won't be a good map.