If one is watching this unprepared then it’s easy to get disappointed, especially if you’re a big fan of all the other Ghibli movies. I’ve seen in some reviews the argument that this is due to it’s heavy usage of Japanese myths and cultural references, which IMHO is quite a stupid argument.
The problem of Pom Poko is not the fact that it’s steeped in Japanese culture, but that it’s a documentary of fictional (and mixed in real) events involving mythological creatures. It’s an interesting and fascinating if not very successful approach. Imagine someone making a documentary about the extinction of unicorns and tries to weave in a message about the real destruction of animal habitats due to urbanization. Fascinating yes, but also boring and involuntarily hilarious at times.
The Entropy Pump 