I'm not sure, but the walking missions (whether they're good or not) do not seem like they're going to be a large part of the game. They showed it in multiplayer, but I haven't seen a big presence in the main game, from the videos I've watched. I think they wanted to stress that it did have walking, particularly in multiplayer, and people felt as if the game automatically did as well.
As I said, I really don't know, but I don't see this having that many walking missions. I can also see missions that will be part walking (Arwing goes down, find the Landmaster, something like that).