Why is using a Gamecube controller on Smash such a big deal?

[Cheebee]

padib said:

KylieDog said:
It's a crutch for SSB players as lets you do things other controllers don't.

Why is it a crutch? Was the series meant to be played with controllers that let you do less?

I'm also wondering what the pro controller is lacking that the cube controller offers.

Well, analog triggers, for one.