[blhack]

Because most of the parts of the world that are designed, are designed for bipedal things that occupy about 1.5 feet^2, and are about 6ft tall.

Think about bigdog trying to walk through a house. It would have a lot of problems, because the house wasn't designed for something that looks like that.

[rralian]

Well, actually big dogs do quite well walking through a house. They're quite popular. They just need to make BigDog a little smaller, and I think the four-legs approach would work quite well.