The genius of the Orks in 40K is they're stupid. Think about all the other races in other science fiction settings you can remember, how many of them were stupid on purpose? Every sci fi setting wants to push really hard that all the aliens are hyperintelligent entities worthy of the reader's respect, but not Orks. The closest thing to a stupid race in Star Trek are the Klingons, but they're not stupid, they're a warrior race with a defined hierarchy similar to the Orks, but they're still an educated, intelligent species that mingle with other races in the Federation.
You can't fuck up writing an Ork the way you could a Vulcan, if an Ork does something stupid in the broader context of the situation or the setting, it's because it's an Ork and not because the writer is dumb. Being intentionally retarded is what makes Orks truly unique in sci fi in my opinion, because writing the behaviors of one is that much more flexible than writing stringently defined races like a Vulcan or Eldar, an Ork has room to make basic mistakes that a space Elf would never make and aren't held to high writing standards, because you don't have high expectations for them as characters, the only behavioral expectation of an Ork is to fight.
