The Wii did plenty of third party support ...
Zumba Fitness, EA Active, Guitar Hero, Just Dance, etc.
You can't champion a console that's mainly a casual platform and then get upset that the majority of the games were casual-centric.
The Wii was never an alternative for games like Call of Duty or Grand Theft Auto or things of that nature. Those games always sold better on the XBox/Playstation brands and the experience of those types of games would always have to be massively compromised on the Wii because Nintendo decided to recycle the GameCube chipset.
Wii got what it deserved in terms of support. If Nintendo wanted the core third party titles, they should have made a proper HD system, they didn't.
They had a good thing for a few years, and it fizzled out, as fads do. That's all that happened.
Even Nintendo didn't have any real great success with "traditional" games on the Wii outside of the Mario branded games in general on the Wii. Metroid Prime 3, Sin & Punishment, Xenoblade, Punch-Out!, Excitebots, Zelda: Skyward Sword ... none of these games were blockbuster hits despite having a massive userbase to sell to, in fact a lot of these types of games really didn't sell any better than they would have on the GameCube. It's basically just DKC, Smash, and TP that did quite well on Wii, and then Mario games, and that's basically it.
