Elessar, you miss so much.
And you sound like someone who's only ever played one roleplaying system. I like the "from the ground up" system just fine, thanks. I've played it many, many times.
I started playing D&D when it was AD&D, and I was a strict adherent to the rules, which rather forced players to start from lowly beginnings and scrape for those great rolls which allowed you to do something truly heroic. My DM, on top of that, was a historical realist. Before 3.5's armor rules, he used to have our characters help each other don armor for the sake of accuracy. So you needn't talk to me like I'm a child seeing the world for the first time.
I've stepped outside Plato's cave, and further than that I've hopped on rocket ships to other planets where gravity as I knew it no longer existed. I've played superhero systems that inflate my characters abilities with amazing powers right from the start, as well as horror games that put me in the dark with a snarling monster armed with nothing but a flashlight.
The point I've been trying to make is that the system suits the genre. In the aforementioned horror genre, players are weak not just at the beginning of the game, but all 20 (or whatever) levels of play. Why? Because that's the point of the genre. When I'm playing a horror game, I want to be scared. And I don't need a system that simulates reality exactly to do that.
In game mechanics, there's an invisible scale of realism. On the one end, we have complete and utter freedom. Whatever the players want their characters to be, they are. They tell the DM what their characters do, and they do it. The DM tells them the effects of their characters' actions on the world. On the other end, we have the DM hunched over a calculator making physics equations, and player characters constrained by the physics of their individual character. Every action they do, even if it is lifting a pencil, is a triumph of the player's will over the quantum mechanics that govern the imaginary universe. Both your D&D game and my D&D game are in the middle of this scale, but mine is about an inch more towards the former, and yours is about an inch more towards the latter.
In any case, I don't need to be sold on the "from lowly beginnings" shtick. It's a style, not the end all be all. And the mechanics you're advocating support that style. You sound like you like that style, to the point of waxing poetic about it. I think that's fantastic. I've played it, and a great number of other styles of play. If you think that yours is the only rewarding style of play, however, then it is you my friend, who are missing much.