The reason is simple, yet ironic. DMC games sell mostly outside of Japan, so Capcom decided to concentrate on the western fanbase. They tried to raise the appeal by giving the game a "western touch" (There was a reason why I used that expression in my previous post), somehow not noticing that it's the crazy jap touch that makes DMC DMC.
http://img543.imageshack.us/img543/8680/mynameisdante.jpg