My bad i misread the post

I wonder how many silent protagonists are reading this thread right now and wishing they could comment on it?

<points to himself, trying to make people notice him>
Oh, wait, sorry, I already commented earlier.

yeah and it'd be out of character for you to shut up
ever

...

Yes, it says "He's a moron". Noone is saying he should make funny quips every time he blows a bad guy away. It's just that when someone who cares deeply about him puts their hand on his shoulder, looks him into the eyes and asks if he's alright, ignoring them completely does speak volumes about his character.

Silence is most effective when there's contrast.
*MINOR SPOILER*
Take the start of Mass Effect 2, you're on the normandy, alarms and explosions all over the place and when you finally reach the main deck and open the door into the vacuum, see the giant hole in the hull, floating debris in the CIC, malfunctioning galaxy map and there's no sound but shepard's breath, it's really powerful and a bit shocking to see the extent of the damage
*END SPOILER*
When your character is asked a direct question, either he or you should reply. "Hey gordon, are you okay?" should be followed by an option to select dialogue or gordon saying "yeah" or "no". Empty silence implies that something is wrong with the annoying mute bastard

I think depending on the type of game, it's not really necessary to have a talking protagonist.
In Shadow of the Colossus for example, Wander don't say a single word, but the game is great.
Of course, if is a RPG, I expect the protagonist to at least say something :/
About Gordon Freeman, maybe Valve is afraid about fans reaction? (Gordon was always a silent character, and then something happens, now he is a babbler!)
Or they are just too lazy to search for a people with a decent voice. :p

Hey does say one single word "Agro!".
Anyway, Shadow of the Colossus is a somewhat different example because there isn't need for Wander to speak. Nobody talks to him, save for a few orders from the shadow people. Otherwise he is almost entirely alone.

Yeah, I forgot about that. :p
That's the point, some games don't need to have a protagonist that talks.