That's not why it's designed that way. They had one of these at my university Robotics department and it's really quite interesting. It's designed to mimick a baby because it's intended to be used to study artificial intelligence and cognitive computing, which is really all about neurology.

Babies are extremely important to neurology. They start with no real knowledge of how to interact with their own limbs and by firing off random neurons and witnessing the result of their own limbs they gradually figure out how to move which limbs and what neuron patterns result in what behaviour. This sort of limb mapping feature of our brains is also the reason that cybernetic limbs can work at all.

Through machines that mimic a child's environment we are developing cognitive computers that emulate how our neurons work. These sorts of experiments are leading us to understand neurology and early human neural development better, as well as how to emulate this to achieve artificially intelligent machines that can learn and adapt.

tl;dr no-one programmed the baby robot to crawl on the floor, it figured it out on it's own.