It sounds like the idea behind this is simply to encourage people to play OOTP, not to give points for whooping up on the AI.
It that's true then I wish they'd open this up to all kinds of solo play. I build solo leagues to be challenging because otherwise I'd be bored, but I don't like the restrictiveness of Challenge mode. Especially having to stop play every week. For a GM only player, that's like doing a cross country drive and having to stop at a red light every 100 ft.
