DeduS on 03 June 2013
After Lufia II released every composer just said "fuck it - we can't beat that" and that's why there is no more awesome boss music. 
http://www.youtube.com/watch?v=hT8FhGDS5qE
http://www.youtube.com/watch?v=SOQjrtZy0a8 (awesome metal version of the same song)
actual answer: I think one of the main problems is the rise of western games - they tend to be more like movies and use atmospheric music, which is just not as memorable/catchy.
