I mean I've played Dungeons & Dragons campaigns where the Dungeon Master wrote a bunch of pre-made character designs and laid them out for all the people who were invited to the campaign to choose for themselves. I think this method definitely helps to streamline the process of starting a campaign with friends, not everyone wants to spend hours researching the perfect type of character to build.
With that said, I feel that a pre made character takes away one of the fundamental perks of playing these kinds of games. It's one thing if you are playing a video game Role-playing Game like say Final Fantasy. Obviously in that kind of Role-playing Game you are "Role playing" a character that has already been generated for you and he or she has their own interests and logic behind their decisions. But is that the deepest role play can get?
I feel the deepest role play experience is always felt when you are the one who created the character yourself, you understand that characters quirks and personality completely because you are the one who designed him (Or her). When you role play a character you designed you really feel like YOU are that character. And that makes all the difference.