In Halo, there are large mechanized suits called Mantises. These are heavily armed and bipedal (kind of like the the AT-ST). There is no doubt that they can be built, but why would they? What would the advantages be of a bipedal mech suit?
The page you linked says that they're about 5.7 meters (18.8 feet) tall. My immediate thought is that this height advantage should be used. The operator of the drone would need to use it to face enemies that are pretty big.
- Large aliens that could rip a human in half
- Large military/armored vehicles
- Other large mech suits
- Large animals (maybe we're waging a war on elephants)
A human - even a heavily armed one - would have problems taking one of these enemies down. A mech suit would have it easier.
Mech suites are great, but bipeds are a bit iffy
Three reasons why:
- Use tools built for humans: A human shaped mech suite with human shaped hands would not require redesigning tools or weapons for the mech to be able to wield or use
- Intuitive to operate for complex actions: Human drivers have years of experience operating human shaped bodies so it would be more simple to teach them how to do very complex moves in a biped.
- Move through human shaped spaces: The stairs, doors and ladders of our world are shaped for easy use by humans, not mechs on tank treads maybe the need to move in human shaped spaces is enough.
- Bipeds are slow: The record speed of mechanical or organic bipeds is 60 mph, the current record speed for wheeled vehicles is 763.035 mph. You are 10 times slower for being a biped.
- Bipeds are unstable: A quadruped or a hexapod can walk in a statically stable manner. If frozen at any time it would be balanced and upright. A biped must be constantly leaning or stepping to keep balance. For examples, look at the recent DARPA robotics competition.
The number one answer is they would be super cool especially in animation.
Another reason would be fast movement over unpaved terrain. Obviously, our tech is not there but if you wanted to get up and over bombed out buildings and what not being able to climb over them would be a boon. A better design for this would include hands or be a goat-bot. If the desire was to Run Ostrich style across broken roads guns a blazing the mech shown could be a solution.
But looking cool would be the best reason.