[KennyBlanken]

Shape ! = center of gravity. All the power and movement stuff is likely very close to the ground, and thus the robot very difficult to tip over.

https://www.dannyguo.com/blog/my-seatbelt-rule-for-judgment/

[jcrawfordor]

I'm not just inferring from the shape, the operational history of these things suggests that they are very prone to falling over.