I get that it's not everyone's cup of tea, but I liked how they did this in Cloud Atlas to visualize the idea of reincarnation.

I think it's more like humans aren't very good at reading the rest of the expressions cats typically use with one another. We are much more responsive to meowing than most anything else in their lexicon, so it becomes their way of communicating with us.

I do think when I'm paying attention to my cat, I can read her other signs better. She usually meows to get my attention when she wants it.