I’m far more interested in how a character grows than how it reads right after creation. I play slowly, and developing the character’s story is the most important thing for me. I’d say that my investment in the game is my reward.
This is true to an extent for me. I need to have something in particular that interests me about a character, though, in order to invest the time in the first place. Something that makes that character stand out in my mind.
If all characters start from the same place, and all character development occurs during the game, then backstory is unimportant. Character development during play will hold my interest for the first couple of play-throughs, but my interest will fade as time goes by.
This kind of character development is exactly what you find in the Gothic and Two Worlds games (in fact, some of Skyrim's approach seems to be peculiarly lifted from Gothic 2!
(Narrow beginning choices, "Chosen One," Character Development during gameplay, Perks, One-piece armor, and even a Dragon Menace.))
Such games tend to interest me enough to play them through the available plot-branches (two or three characters, maybe) but they lose my interest because I can't really bring my own "story" into the game.
In Morrowind and Oblivion, there is nothing spelled out about the player-character, so one is not prevented from imagining any particular background. The Class-building process then allows one to "construct" that beginning character to fit the backstory. I find that this backstory is important, because it predisposes my character to make certain choices in the game, leading the character to become even more "unique" as the game progresses.
As I said previously, I don't play Skyrim, so I don't know how it actually fits into this discussion. But based upon my experience with other games, I think I would miss the ability to preset the character in some way.