Out of the hundreds of rpgs I have played in my time, there's only been a handful where the main character vocally says anything. It would be nice to get a sense of what your main character sounds like, but I guess it would be too much work to accomplish.
I think there are other valid reasons for *not* doing it. In how many players' heads do their heroes sound like stronger, maybe more mysterious, perhaps even sexier versions of themselves -- whether or not anyone wants to admit it? And how likely is a recorded hero voice to live up to the illusion?
It's like reading a book instead of watching a movie. Sometimes your imagination is just better. <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />