I suppose it's because the west has a habit of viewing animation as kind of throwaway material. Most western animation refuses to take itself seriously, which is good for comedy but doesn't allow much depth.
A heap of Pixar stuff and Avatar: The Last Airbender are the two most obvious exceptions to this that I can think of. So a lot of people watch anime because it is truly different to most western animation.
The obsessives are just weird though.








