It's the true voice. If you truly believe games are art, you'd treat them like every other medium, where it's preferable to watch the movie or work in its original language the way the director intended.
You may LIKE the dub of whatever it is, but it's not the original. For example, this has nothing to do with Japanese voices specifically, to be perfectly honest - if it was a German movie that was dubbed with American voices I know I'd want to hear it in German, not in English.
The dubbed movies argument is a poor comparison, dubbing over real people always looks/sounds horrible regardless of the quality of the acting