I don't care for them, personally. The whole thing seems to have a very "emperor's new clothes" feel to it, as if it's trying to justify a lack of content.
My major problem is the idea that silent protagonists are the "ideal" protagonist. To me, that's like saying the "ideal" book should be written in second person so the reader can project their own emotions into a story. There are plenty of great stories that would be much better suited to having a vocal protagonist.
The only two examples I can think of for a well-executed silent protagonist are Chell from "Portal" and Jack from "Bioshock."
Chell was an effective narrative choice that allowed the real star of the show, GlaDOS, to take the spotlight. She's already been mentioned above.
In "Bioshock," the premise of the game is what to ask what morals you'd impose over an amoral society. Keeping Jack silent enhanced the choice system without breaking any walls. The character never gets the chance to talk directly to another character (one-way radios and tapes), and your character communicates entirely through his actions. After all, it was Andrew Ryan who said "We all make choices in life, but in the end, our choices make us."
If we look at "Half-Life 2" in comparison, the silence doesn't particularly enhance the game's experience. All it really does is continue the fact that Gordon Freeman doesn't speak in the original "Half-Life." In HL, it seems that this would have been more of a practical rather than aesthetic choice in order to save disc space and voice-acting money.
In contrast to Jack, Doctor Freeman has direct interaction with other characters. While this isn't a bad thing by any means, it can quickly break immersion. I always felt that the characters were talking "at" me rather than "with" me in the Half-Life series. In the original survival-action-game, this works just fine, but the style of the HL2 series isn't at all conducive to that choice. If HL2 was the first game of the series, I'd reckon the chance of having a vocal protagonist would be *much* higher.
Just my two cents on the deal.
