While the situation is worse in Europe, a lot of your complaints really don't have much to back them up. There are plenty of games just as violent as GTA on Nintendo systems, and True Crime: Streets of LA looks to have even the same style of gameplay with top-notch acting, an original soundtrack and the whole nine yards.
GameCube, more or less, is Nintendo catching up with their previous mistakes. They are getting publishers like Capcom, Square, and Konami back, and although it's taking time for them to get games out for GC, those relationships will be much stronger by the start of the next generation.
Still, even saying that, I have over 30 GREAT games for GC and haven't had time to finish them all. There are a couple genre gaps like RPGs, but overall, there isn't much to complain about.