I know that a lot of people that ask for representation in Planeswalkers are looking for someone who looks like them, but that is not the only representation that many of us like. We also want to feel a mental similarity as well. Some of us don't necessarily see ourselves AS human. And while the vast majority undoubtedly do, it is still a reasonable request to, at least a LITTLE more frequently, have non-human Planeswalkers. Especially of a race that hasn't had one yet. Ex. Khenra or Viashino.
It’s not as if we haven’t made a bunch of fantasy creatures into planeswalkers. Currently in the pantheon as cards, we have:
Whatever Ashiok is
We’ll make more, but it’s not as if we’ve been ignoring non-human races.