There's something really fascinating about robots. There are a whole lot of people working on the problem of humanoid robots, and it won't be that long before they become efficient enough to do some jobs currently done by flesh and blood people. It's already happening in millions of factories, but when we see something that's just two joints attached to a welder, it doesn't do much to spark the imagination.
Human bodies are inefficient for most of the stuff that humans do in the modern world. Legs are a great example of this - we don't really need them most of the time. Wheels are a more effecient form of locomotion, so long as you're just traveling around flat places. Given the ever more handicap-accessible world, it doesn't make real sense for a robot to have legs in an urban environment. On top of that, gyroscopic technology is now at the point where we can have the wheel equivalent of bipedal locomotion - the Segway is exhibit number one of that. This further reduces the amount of space required for wheels.
Another way that robot bodies can improve on the human design is with the hand. To pick up any object requires a maximum of three "fingers". Two fingers are needed to grasp an object like a pole, and three fingers are needed to fully enclose a small object. And of course only a single finger is needed to poke something. Besides that, the designs just look cooler than the hand. We talk about the thumb being opposable, but with a robot hand all the digits can simply swivel around a base, making them all opposable to any other digit. Besides picking up and manipulating objects, the thing we use fingers for the most is data input, not just in the typical example of hammering away at a keyboard, but more subtle forms of data input like playing the violin or doing long division. Mathematics has already been completely outsourced to computers, and the ability of computers to reproduce sound has been proven to such an extent that it seems trivial to point it out. And yet people keep trying to make a robotic hand that looks like the human one.
Here are the arguments in favor of more human robots:
The Argument from Aesthetics
People tend to be uncomfortable with new things. If a robot looks at least a little like a human, people will be more accepting of it. This is especially important in the field of healthcare, one of the primary focuses of Japanese robotics. A humanoid robot is more pleasing to the eye, which means that it's actually worth solving some of the more unique engineering problems associated with that.
The Argument from Backwards Compatibility
Almost everything in modern civilization is designed for humans. In a way, humans represent the dominant form factor; an industry standard to which it's wise to comply. Having a robot made to those specs means that it is guaranteed to be able to interface with objects and machines that humans use. In almost all cases, this won't be the best solution - but once the generalized problem is solved, suboptimal solutions become cheap enough for that to not matter all that much. Think robot chauffeurs; they actually make sense if the economic variables are right, even though that solution makes much less sense than an on-board computer with sensors.
The Argument from Augmentation
Robotics doesn't just apply to robots. One of the major areas of advancement right now is in prosthetics. By making robot arms and hooking them up to people, a robotics company can expand its market by a large amount, as well as being able to secure both healthcare and defense grants.