this is so true. It looks like Mario and Luigi gang up to screw Blue Toad together.
I think it's called "having fun."
The point is that some friends are playing Mario together. What do people do with Mario games, they run around pointlessly having fun, ignoring the point fairly often. This is part of what makes a Mario game great, that the world and the physics are fun to explore and play around in. The co-op is less about working together (it seems) and more about having that experience together...
That being said, I just explained to myself why online isn't all that important... I'd still like it and I think Nintendo underestimate the power that this with online co-op Wii Speak would have had.
I would cite regulation, but I know you will simply ignore it.