Its current intended military application is to carry equipment. Ammunition, spare parts, weapons, food and the like. Many US Army soldiers carry 70-80 lbs of gear into combat. The idea is to lighten that load by having machines carry some of it, in order to save lives and shorten conflicts. Wheeled vehicles don't work on a lot of terrain types, hence robot dogs.
Robots don't feel pain or a sense of injustice when you kick them. It's no different than kicking a washing machine or a car tire. It looks like an animal out of necessity, to be able to follow humans while walking over uneven ground. But it's just a device. If it can't take a few kicks how can it be counted on to climb a hill or navigate a jungle?
Somewhere out there, a 19 year old kid is about to carry 80 pounds of gear on a 10 mile march in order to be shot at upon reaching his destination. The only thing he cares about is living to see tomorrow's sunrise. Kick the hell out of the damn robots.