In the original bg games and DA:O the "silent protagonist" wasn't a silent protagonist--they were just unvoiced. The dialogue is there in text form. This is likely a design choice since unvoiced gives players a lot more flexibility with RP. DA:O, for example, had significantly more dialogue choices for the player than DA:2 and DA:I because the protagonist wasn't voiced. Hawk, Shepard, and the Inquisitor were all given personalities (with some flexibly therein) that were within a limited confine created by the writing team and the actors. An unvoiced protag can be whoever you want them to be with whatever personality you want since you fill in their voice in your head. (Try reading the dialogue choices as if you're reading character dialogue in a book. I don't know about you but when I read books I fill in the dialogue with all sorts of voices with different inflections, accents, and attitudes.)
I like voiced protags in some games, (ME did it really well) but in games with a heavy emphasis on RP I prefer unvoiced.
