Don't forget that the 360 was available a year before either of the other two consoles. With it being the only, then, "next-gen" console available at that time, it was bound to give Microsoft a decent start. I'm also of the mindset that, currently, they have the best selection of titles, offering a good bang for your buck.
As for Nintendo's tactic being stupid - whatever the case may be, I still hear at least a small handful of inquiries about when Wii's will be on the shelves again whenever I'm at a Future Shop, Best Buy, or the electronics section at a Wal-Mart. Creating a high demand is never a permanent solution, but I'm not going to fault Nintendo for using the strategy for as long as it's going to work; if that's what would make my product sell like hotcakes, I'd employ the same strategy.