In my opinion, there should be a section where you can submit your runs. Some people like my self like to speed run the game but use an emulator. I take vote in putting a section for emulators in there. Just like Super Mario 64. Every user of emulators deserves a chance.

Emulation of games from the gamecube era and onwards is much less accurate and reliable than that of older console generations. For NSMBW specifically, loads don't match up with console versions, and the nature of emulators being able to modify aspects of the game (changing framerate, etc) and run input recordings is something we dislike as a community. You will find that many popular games from more modern consoles ban emulators as well, likely due to similar reasons. While I agree that more available platforms for speedrunning is generally a positive, the situation with emulation for NSMBW specifically makes banning emulators such as dolphin the best option for now. :)