Trying to work through the algorithmic burden. Would a home robot's navigation software be more or less complex than a self driving car? No lane markers, stop signs/lights. Environment changes constantly with doors open/closing, pets, humans moving around, stuff on the floor. It would be more like apples-to-apples if we were talking about a self-driving off-road vehicle.

Not to mention, the auto is doing something useful simply by moving. Perhaps a security robot in the home could be valuable by simply moving, but otherwise, it needs an additional layer of application. Interacting with humans, manipulating objects which it would have to identify, ...