Before I started watching Star Trek, I had heard about it on the Big Bang Theory. The way it was talked about, I was expecting a franchise with very airtight and complex lore. In reality, it’s kind of a muddled mess. And really, it’s better the creators don’t worry too much about continuity, why let continuity get in the way of a good story? It doesn’t make sense that half the cast of the original series had encountered Trelane before but in the end, does it really matter?
Anyway, fans of big franchises who keep track of all the lore and act as though it’s all consistent, put way more thought into continuity than the creators.
Then there is Stargate SG1 that, especially if you have the dvds, are fully aware of continuity errors and apologize. They have said a few times that they did something that was necessary for the episode, later realized it was kind of stupid, and then ignore it in the future until they can reference it in a Wormhole X-Treme! episode or such.
40k on the other hand seems to have overall gone with the idea that it’s all screwed up and full of unreliable narrators anyway. The fact that things contradict each other is just on theme for the grim dark.