Freeman isn't a character. He just happens to be you. Snake is a character. Do you see the difference? Barney is more of a character than Freeman is. Put it this way, Freeman as a character is roughly on par with Doomguy.
Then you need to redefine your views on what a character is, because you are wrong.
His a fictional character in which you play and due to the way Valve made the game, the character does not talk, the story is heavily orientated about it being told from other characters in the game. This does in no way not make him a character.
If he wasn't a character he would not have a pre-determined name, have the entire game revolve around him, history/future changed by him, have posters and pictures of him for game advertisements and lastly, be so well known in the gaming community. If he is not a character, what is he?
Being a character does not have certain strict requirements, there's such a broad variety of reasons why someone/something can be one.
Next time you try argue what a character is maybe know what you're talking about.
what do you learn about freeman?
Either you've not played the game or you clearly didn't think hard enough!
Everything you learn about Freeman is through the game, as he does not speak, information is gained from other characters dialogue/gossip/background script. Not only that, there are odd things left around the game world for you to read and explore.
Unless you're one of those people that some how are oblivious to all of this whilst playing, then maybe you can enlighten me on
how the hell you missed that obvious point. 
