I don't think they're necessarily better at writing lyrics. Some of the worst lyrics I've ever heard have been by Asian artists. But I think Asian languages are much more suitable to things like poetry, art, and music. They are much more vague which more easily permits discussions of the surreal and beautiful, whereas European languages (English, especially) are very, very, very highly calculated and scientific. European writers could write the same things as Asian writers, but it would sound so jarring and not very musical. I think there are a lot more boundaries with European language lyrics.