Whenever someone attempts to build a humanoid robot (an android), whether it's Boston Dynamics or a hacker in a garage, they usually have one or several justifications for it. I'm going to list the common justifications here and explain why I think they don't make sense, except for one of them.
Perfection. Humans are the pinnacle of evolution and our bodies are the most perfectly matched to operate in this environment. Bullshit. Our bodies were optimized for many tasks that robots simply don't do, such as growing, giving birth, running very long distances, resting, mating, raising young, etc. They were also optimized around constraints that are simply not there for the robots, such as limited material strength, high cost of precise sensors, limitations of energy distribution, need for regeneration, inherited overall structure of mammals, etc.
If you reconsider the needs of the environment and the possibilities the technique gives you, you will come up with a construction that is smaller, lighter, faster, has much more reach and more flexibility, has eyes and other sensors practically everywhere, and doesn't look anything like a human.
Teleoperation. This is what many giant robot movies claim -- you build a robot, and make it repeat all the moves of a human pilot, only with greater force and often in larger scale. There are two reasons why this doesn't work. First, if you really make the robot considerably larger, you are going to have completely different dynamics. Even if you make the robot's actuators super-strong and fast, so that you can compensate for the dynamics in software (you can basically simulate any dynamics, as long as you have enough torque), this is going to be very inefficient and awkward.
Second, there is no reason for that robot to still have human proportions. The pilot would need to learn to operate the robot anyways, there is no getting around that, and our brains are very flexible -- we could easily operate a body that has completely different proportions -- much better suited for the task at hand. For instance, a chimpanzee can run much faster than a human.
Man-made environments. If it's going to be used in environments made for humans, and use human tools, it has to look like a human. Again, not true. Technology can do much better. It doesn't have to have the same size, strength and reach as humans do -- it just needs to be smaller, have greater reach and be stronger. It doesn't need to be humanoid. In fact, if you have a dog, you can already see that it can operate in human environments just fine, even though it's much smaller and less agile. Something like RoboSimian is going to operate in human environments much better than humans. As soon as it has good enough control, that is.
Blend in. It will be easier to interact with and get used to it if it looks like a human. That's actually exactly the opposite. You see, we appeared on this planet together with several other species of hominids, and we have evolved to exterminate them with extreme prejudice. Whenever we see something that looks like a human, but not quite, we find it extremely creepy and disgusting. This is called "uncanny valley" and it's a big problem. The easiest way to avoid it is to not make robots look like humans.
It's cool. This is the only reason I can accept. Yes, it's insanely difficult, it requires a lot of research and it's expensive. All the more impressive! It totally makes sense to make humanoids for entertainment purposes, to put them in shopping windows, TV shows, live performances and what not.
And that's pretty much it.