I was thinking about this the other day because of the furore over the decision to have him go back in time rather than Kitty.
In the film it does make more sense for him to go back, and really, although the film is told from his perspective and follows him around, he doesn't do an awfully lot in it. He mainly stands there while other characters steal the limelight.
So yes, he does have a fair amount of screen time, but to a non fan, I don't think it ruins it.