I think choosing a silent protagonist should depend on exactly whose eyes you want the story to be told through. If you have a set player-character like Nathan Drake, then the story is going to be "Uncharted--as interpreted by Nathan Drake." Or perhaps more accurately, "Uncharted--as interpreted by a fly on the wall observing Nathan Drake dealing with all this shit." In the Half-Life games and Portal, the story is told by the world around you. There are all sorts of stories in the environments and the NPCs in the HL games, and a good portion of Portal's story is told through the environments and the general state of Aperture. These elements that the player is supposed to slowly soak in would be undermined if they were constantly being filtered through the player-character's stream of consciousness. Or at the very least, they would be significantly changed.
So silent protagonists work for HL and Portal because the story is intended to be viewed through the player's eyes. It's not about the player learning about how Chell feels about Aperture, or how Gordon feels about the G-Man, or any of their emotional journeys. It's about the player experiencing the world and taking their own emotional journey.
So silent protagonists work for HL and Portal because the story is intended to be viewed through the player's eyes. It's not about the player learning about how Chell feels about Aperture, or how Gordon feels about the G-Man, or any of their emotional journeys. It's about the player experiencing the world and taking their own emotional journey.