You really don't get it at all. Its not lazy or dated, in fact its one of the few methods that actually pushes game story telling in a direction other than cut-scenes which are nothing more than a copy of films and movies (that tends to turn out crap I might add). For starter the KoToR dialogue system whilst good, is somethign entirely different to what HL2 is trying to acheive.

It never breaks from his viewpoint, that alone helps with the immersion. It doesn't make you pick dialogue choices, which make you realise you're playing a game. You never hear his voice or any of his personality, because the game leaves YOU to fill in the blanks. It gives the player complete control over what sort of person Gordon Freeman actually is. It fills the world with lots of characters to interact with and is meant to give you the opportunity to decide what should be said at each stage without Gordon saying anything, as then you'd have a voice speaking that wasn't your own. Gordon Freeman is made a lifeless shell to give you the player the chance to use your imagination to give life to his actions.

SPOILER: At the end of Episode 2 I genuinely felt helpless to the events unfolding because I was being held in place, whereas in most of the game even when people are talking I'm free to wander round and dow what I want.

You sound like you're one of those annoying people that go to the movies and if the story is not simply handed to you on a silver platter then you don't like the film.

Finally, to your last sentence have you player any Call of Duty (or Medal of Honor actually thinking about it)? Your character is silent throughout and is nothing more than a soldier. The story unfolds around you. That soldier only has a name, I don't think you ever get to see what your character even looks like. At least Gordon Freeman has that!

The game doesn't allow you to fill in the blanks....
For example, if I wanted to help the Combine, could I? No. Can you reflect your personality in the game in anyway? No, you can't as the game has been designed to be completely linear. Not that that is bad, but it begs the question what is the point in a mute protaginst? As I have said before, the illusion of being someone is completly broken when you have to approach the game from the same angle every single time. KotOR's dialogue system allows you to fill in the blanks as your personality has consequences in that virtual world.

If I wanted to use my imagine to fill in the blanks, I would read a book etc. In a medium such as gaming, where you are meant to be part of a truly virtual world, to then say "Oh yeah, fill in the protaginist with your imagination" seems absurd and completely withdraws the person from the expereince, as they are having to literally make up parts of it.

What I simply dislike about HL2 is that it feels schizophrenic. It wants you to be part of a different world, and then slaps you back into the real world if you try to treat the game as such. Thing with the CoD series, yes you never see your character(s), but that's because you are part of a bigger picture e.g. the world wars, whilst hopping all over the world. In a game where you are the classic cliche Rambo, I don't understand why they decided not to give the main character any identiy, and then were so highly praised for it.

I'm playing through HL2 again to see if I missed something out last run through, but so far, no such luck.

The game doesn't allow you to fill in the blanks....
For example, if I wanted to help the Combine, could I? No. Can you reflect your personality in the game in anyway? No, you can't as the game has been designed to be completely linear. Not that that is bad, but it begs the question what is the point in a mute protaginst? As I have said before, the illusion of being someone is completly broken when you have to approach the game from the same angle every single time. KotOR's dialogue system allows you to fill in the blanks as your personality has consequences in that virtual world.

If I wanted to use my imagine to fill in the blanks, I would read a book etc. In a medium such as gaming, where you are meant to be part of a truly virtual world, to then say "Oh yeah, fill in the protaginist with your imagination" seems absurd and completely withdraws the person from the expereince, as they are having to literally make up parts of it.

What I simply dislike about HL2 is that it feels schizophrenic. It wants you to be part of a different world, and then slaps you back into the real world if you try to treat the game as such. Thing with the CoD series, yes you never see your character(s), but that's because you are part of a bigger picture e.g. the world wars, whilst hopping all over the world. In a game where you are the classic cliche Rambo, I don't understand why they decided not to give the main character any identiy, and then were so highly praised for it.

I'm playing through HL2 again to see if I missed something out last run through, but so far, no such luck.

Well, yes it is linear, but the point of the mute protagonist is as I have said, to maintain that YOU are Gordon Freeman. You have the story unfold before your eyes as you decide to experience it. The story might be limited, but its the little things you notice in the game that make the story special. The whole point is that you don't have anything to serve as a reminder that you are playing the game. In games like KoToR, you're constantly reminded of the fact its a game by having the dialogue constantly asking for input, but that's fine, its an RPG where that is needed. In a FPS, where the action is far more intense, having that would break immersion.

And leaving things to your imagination is actually where a lt of the older games have their charm, especially in the RPG genre. Take games like Planescape Torment which is heralded as having the best writing in a game. The technical restriction of the time meant you had to use your imagination to fill in lots of blanks because the tech wasn't there to animate it. What Valve did was make you feel like you are Gordon freeman rather than a player that controls someone else with a seperate voice and seperate personality.

I'm not sure what you mean by schizophrenic, I always find myself immersed in the 1984 style world Valve created. Maybe you should go back and play HL Source, as that was set in more modern times before the Combine. Might be why you feel it's a different world but with elements in reality. Just note its a 1998 game.

"As you decide to experience it"

How is my experience going to be any different to any one elses?

Everyone's experience of a game, will differ slightly, even in linear games. There are subtle clues and hidden messages within the game which are there for you to pick up should you wish to.

"The whole point is that you don't have anything to serve as a reminder that you are playing the game."
Other than the invincible NPC's, and being mute..

Neccessary evils, I've already explained the point of him being mute and you really don't seem to understand the concept at all. The invincible NPCs are needed to tell the story and when something does finally happen to these characters, make it all the more shocking.

As much as you keep saying "You are Gordon Freeman", well, what's the big deal with that?

Because the game keeps building up Gordon Freeman as the saviour and the one "Free-man". Essentilly saying that this whole world is dependent on the actions you take in the game. YOU are important. Very few other FPS games subtlely build up a character so well, a character that is actually the player, even though he's got a seperate name. In CoD, you're just a lowly soldier (who gets asked to take out all the important stuff), in UT2004 you're a nobody, practically a drone in countless thousands, in Doom3 you're just no-name, no mates Doom guy. 

In any other FPS you are someone else. In UT2004, you are yourself. In the CoD series, you are a soldier. As HL2 is limiting in the world it presents you, it never truly feels like you are actually someone as you are herded every step of the way, just with invisible methods e.g. linear path, invincible NPC's etc. The problem I find is that HL2 is far too scripted. Every event just has NPC's talking at you rather than to you. I can be bouncing around a room or messing with props and the NPCs carry on almost like drones. Yes the game is technically limited, but the fact that you never get to speak winds me up and it feels like I'm just a tool with a gun rather than a living, breathing character in a living, breathing world.

Do you actually enjoy the single player campaign in the CoD games because a lot of the narrative ideas they used have their basis in Half-Life and Half-Life 2. Take CoD4 as an example, everything is hugely scripted and I could bounce around as much as I wanted when Captain Price is talking to me and giving me orders. I'm not sure why you think the linearity is such a big problem. As Reasonable has already posted, every game has restraints and in Half-Life 2 its telling you a story that you get to interact with. You only have a set amount of freedom in any game. And in many games, having choices actually detracts from intensity of certain events. When scripted, the developers can control the experience and devote more time to intense and emotional events.

I'm going to use CoD4 as an example as the best scene from the Half-Life series are in ep2 and I've already mentioned that previously. But take the scene in CoD4 after the nuke has gone off. Its completely scripted, but it still offers you control of your character, almost giving an illusion of control. Half-Life does this and does it well.

I do see what you are getting at and I do appreciate the angle that Valve took. However, with CoD 4, you feel like you are a soldier, part of a war, whereas in HL2 you are just an old-school Rambo. As I said, when I play the game I feel like I'm just a charactless entity running-and-gunning my way around a different world, rather than being part of a bigger picture. Take for example Quake 4, where you felt part of an actual invasion fleet, taking on an alien race, rather than a super-charged Rambo.
I just feel that if Valve really wanted the game to be truly immersive, giving the character some interaction, which seems a much better word than freedom, with the world, would make the game more immersive instead of having 100% one-way conversations.