Orwellian and distopian fiction

Any other authors? There's a lot of bullshit sci-fi distopian fiction which focuses on cardboard characters and childish romantics.

But is there anyone else like Orwell or Huxley, or even Kafka - people with a theory, a focal point, a purpose? Philosophers, not just writers of rattling good stories?

Oryx and Crake, also by Margaret Atwood.