Here's why:
* Different Platforms: The Wii and Xbox 360 are separate gaming platforms with their own unique hardware and software. They cannot directly connect to each other for online multiplayer.
* Game Versions: Call of Duty: Modern Warfare versions for Wii and Xbox 360 are distinct games with their own servers and online infrastructure.
* Limited Player Count: The Wii version of Modern Warfare was designed for a much smaller player count than the Xbox 360 version.
In short, you can't play with 360 players in Call of Duty Modern Warfare for Wii because the game was not designed for that, and the Wii and Xbox 360 platforms are incompatible for online multiplayer.