Fair points. However, I think the biggest problem with a short robot would be people tripping over it. Even if it had a big 'ol arm sticking out like a robotic

Fair points. However, I think the biggest problem with a short robot would be people tripping over it. Even if it had a big 'ol arm sticking out like a robotic giraffe, it'd be hard to gauge the dimensions of the base, especially given it may not be clear what direction it is facing if the arm can reticulate about as it pleases. So, a robot in a human environment must be about human height and width, but also its width should be roughly uniform from top to bottom like a human. I suppose you could build a quadruped of those dimensions, but it's hard to imagine what it'd look like. I am not aware of any creatures like that occurring in nature, likely with good reason.