Well the "spreadsheet" approach works--assuming there's enough variables. My DnD characters are on spreadsheets. But the odds of me finding the same or even a similiar character in any random group are slim to none. That being said: 4th edition characters tend to be more copy-and-paste due to higher restrictions on multiclassing, less feat trees, more restrictive prestige class options and less races/templates for PCs.
But what Video Games have thus-so-far almost always failed to do is make your character what your doing at the time. They make your character=your character's options during an encounter/dungeon. Its like saying Batman is Batman because he's always crazy-prepared...but in truth your arsenal and skills are only a small percentage of your [i]character[/i]. Your character is your background, personality, etc... and not just "how well you faire/what you use against obstacles in life.
Of course, its hard to establish a character in games where everyone does the same routine quests. At one point I tried to emerge myself in WoW towards the lower levels...but seeing people in chats asking for help with a quest I completed levels ago just made me lose any interest. "Kill this guy at this castle? I already did that. Whats the point if he's just coming back to life?"
Of course customized quests with long term and game-changing effects would require a staff devoted to a handful of characters. "GMs" in MMOs, as they are so inappropriately called, are really just bug-managers and moderators. They no more add to the flavor, story or immersiveness of a game than anything else.
And, of course, single-player games are trying to tell their story (or stories) and will inevitibly force you into the same plots that have been completed ages before you get your hands on the game (unless your a developer or beta tester who plays before the game ships).
In the end, playing Electronic RPGs is no better than playing a DnD group that only uses modules with a DM who hates improv.