Maybe Nintendo should have came out with a full-priced Melee 2 on the GC? That, or maybe just more games in general. I think the drought hurt the GC more than anything, and that includes the lack of 3rd party offerings, but I also think Nintendo could have done a lot better too. They were in 3rd place, but they were still profitable and had lots of money so there was no reason they couldn't have funded the development of more games to fill in the holes in the GC's lineup.
So 3rd parties didn't support the GC? Well, fine. But why didn't Nintendo rush in and fill that void themselves? Pokemon and Mario can only take you so far. Sony has managed to carve out tons of new franchises from scratch recently so there's absolutely no reason Nintendo couldn't or can't do that, especially considering how Nintendo has more money and more talent than Sony does. Its such a huge waste to have talent like Retro, but then not let them do anything but Metroid Prime games again and again, over and over. Let's see something new, damnit!
Its also a waste for Miyamoto to be wasting his talent on non-game crap like Wii Music. That's like hiring Stephen Hawking to tutor you in math. Such a waste when he has proven himself capable of so much more.
Nintendo should assign their mediocre game designers to do the sequels and the non-gamer crap. Their star talents should be at work pioneering the new franchises. They should be like the Louis and Clark clearing a path through the virgin forests and then the mediocre talents can move in and keep those paths from getting overgrown, but meanwhile the Louis and Clark talents should continue going on and blazing new trails. Its beneath them to be assigned the role of what is essentially a janitor making sure old franchises are kept fed and watered and cleaning up their poop.