That means they would have had to insert a whole nother set of animations for EVERY one of the characters attacks because Game and Watch was built with sprites instead of polygons. Which probably would have been worth it, but also probably didn't even cross Nintendo's minds.
As for the game, I'm simply stoked out of my mind that it's gonna be online. I can Smash people in EUROPE! Yippie-Kai-Yay!