How warranted a pre-gen character is, is commensurate with how much of a sandbox the game is going to be. If you're playing an RPG with a setting that exists before you make a character then I imagine you would take that into account when making your character.
Games like D&D can be near total sandboxes, but premade adventures often have characters with hooks for that adventure, and systems like Call of Cthulhu which is very narrative, sometimes expect it.

No computer RPG will ever be the kind of sandbox having a living DM will allow, and I don't think most people would be interested in a computer game that tries anyway. It's why I'm not bothered by having origin characters, but I am worried that a custom character might be left behind.

dumb, pseudo-intellectual and polite homophobe