I'm disappointed, Shamus. I clicked this article to see whether you had anything new to say that might shake my opinion, or whether you would bring out the same tired defenses I'd seen a thousand times before. Turns out it was the latter.
Arguments like this one rest on the assumption that, should characters like Gordon be voiced, they will invariably be written badly, with annoying or stupid personalities. I see people point to Other M Samus or CD-i Link and say, "See? If you give characters a voice, THIS HAPPENS!" This, to me, looks like settling for mediocrity instead of atrociousness, when we should be pushing writers to do better than that. Bland is better than bad, as you say, but good is better than both.
Then there's the "canvas onto which I can project my own thoughts." I've heard that so many times it now makes me throw up in my mouth a bit. It might work in games that have no character-driven elements whatsoever, such as old-school shooters like Doom, but for games that give us a rich cast of characters to interact with, it's like assembling an exhibit of exquisite paintings for the Louvre and then placing a blank canvas at the center, telling viewers to "project your own painting." Half-Life 2 tries to sell us on this relationship between Gordon and Alyx, but since Gordon can't speak, all Alyx can do is talk to herself and assume Gordon is nodding along. And that's how everyone acts in Half-Life 2, because really, nodding along is all Gordon can do. The result is that that's who Gordon is--a spineless asshole who just goes along with what other people say, having no input, no agency, and nothing to contribute but another gun and a HEV suit.
But there's a bigger thing. You see, I don't play games in order to "project my personality" onto anything. I'm a pasty white guy who spends too much time in front of a computer screen and types up long retorts to Internet articles, why on Earth would I want to take that with me into a game? No, I play games to forget who I am in real life for a while, and step into the life of someone else. Video games are at their best not when the protagonist is acting as I would act in real life, but when I've forgotten how I would act in real life and become invested in this person who is not me. Sometimes I find, in the midst of a game, that my inner voice has taken on the voice and speech patterns of the character I'm playing as, and that's how I know the game has really grabbed me.
What I take away from this article is that silent protagonists are a decent crutch for writers who aren't capable of delivering rich, well-characterized protagonists. I suppose that's true, but I'd much rather play the games made by the people who are capable.