They might be adjusting for all of them...
I wonder if walking/running is analog still for the control stick based controllers since the Wiimote seems to only be able to walk or run. This whole "Ink Drop" thing could evidence of this: In SSBM, as you probably obviously know, when you dash and then hit the control stick the other way, you turn around and start dashing but you're going a lot slower. Doing this in SSBB, though, seems to make your character fall down, after which they can stand up, roll etc. This could be a sign of limiting you to just running or walking, since you'll never do the slower dash, so as to not leave out the Wii Remote players and maybe simplify the online data.
...Just a thought.