As a matter a fact we can. It is not that we and other animals walk like this because we just decided to like that. There are lot of stuff that influenced this, gravity, as less as possible energy waste ... Same could apply on Mars creatures, at least we have some 'idea' what environment looks like there.
Not thinking about the Earth, life forms on Earth and evolution.
I guess it comes down to our collective self-importance and arrogance of all knowing ,godlike beings.
We don't even know all the species that are inhabiting our home planet, we can't possibly know how the universe works?
What if this creature came to Mars to explore?
Have you ever seen astronauts in their ridiculous walk?
Why are they walking like that? So what about that creature?
Maybe it has some kind of exoskeleton, robot space suit that makes it move like that, how can we know that?
Maybe it moves like that to conserve energy, no needles secondary motion?
Maybe it's just a break-dancing species?
I understand that this creature doesn't walk like a human/animal, and that it violates laws, thus it's bad.
But can we say stop-motion animation is bad just because it's not human enough?