[krapp]

That is stupid, just push them over and they now are useless.

That depends entirely on whether said machines can right themselves after being tipped over.

But, the way I see it, human cities and human technology are made for our bipedal forms, two legs and hands with five fingers and such. Having a robot match that form makes it easier to exploit urban terrain and implements in the environment. I mean, which would you theoretically rather have, a robot that is a vehicle, or a robot that can operate any vehicle it comes across?