Nintendo does need 3rd party titles. There are not enough platinum-status IP's to sustain any console's life cycle. If 3rd party support was so unimportant, remind me again who won N64 vs PS1 era? And guess which N64 game sold more than Starfox 64, DKC 64, Super Smash Bros, and Zelda Ocarina of Time...Goldene ye 007. Stop...and think about that for one second - Goldeneye, a 3rd-party title with no history, no legacy, based on a Hollywood video game, sold more copies than Ocarina of Time.
F-Zero, Pikmin, Kirby, these may be good games but they don't sell systems nor do they sell into the top 10 sales numbers of that particular Nintendo console. And some franchises like Donkey Kong are too inconsistent to rely on. Diddy Kong Racing was a better game and sold more than DKC 64, the successor to one of the greatest 16-bit games DKC (SNES). In fact, games like Wii Sports and Nintendoland have been outselling Nintendo's own 10/20-year platinum IP's. If Nintendo could solely rely on Mario, Zelda, Smash Bros, Metroid, the big names, they wouldn't be in the trouble they are in.
Going the route of old-school game rehashes is nothing but nostalgia. No one wants to play these games anymore and if there was a machine that could erase your memory of ever playing these classic 8-bit and 16-bit games, and you got to play them again today for the first time, you would call them garbage. It's not that they're bad games, but we've moved on to bigger and better games.