I think it is only beneficial to be able to play multiple styles of music, being a well rounded player is key to becoming the best player you can be. At the same time does anyone else feel like they are betraying themselves when they actually try to write a song outside of their usual genre for whatever reason? It may be trying to write a metal song to headbang to, or a soft lullaby to impress your girlfriend with, or an emo song to fit in with the crowd. For example, i love all types of music but when it comes to guitar i am a metal head. I play all sorts of stuff but i write metal music, i cant help it, metal music just flows out of me (not saying its any good) But i have tried to write soft songs a few times (My Ballerina, My Crazy Diamond) and they are huge failures. I think its great to be able to play many different styles of music, but i think you should let the music flow out of you, not try to force out something your not.