Well certain genres are supposed to have short single player modes. That's why they have intricate multiplayer modes.
But unfortunately I think too many devs are using that as an excuse to make a subpar single player mode. Let's look at Gears of War for example. Stereotypical storyline, extremely short, no reason to replay single player, gameplay is nothing new, and overall the lack of originality is apparent. Dev took no time in thinking about the storyline. Really it looks like they had created a game to run a certain engine and be ready for online multiplayer and then at the last moment put single player in. This is where devs need to think about their games again. Single player needs to be put back on a pedestal instead of the backburner for all games. I don't care if its short, just needs to be worthwhile.
