>>18128
Its British so everything is done in the most overtop corny way.
Try reading the lore sometime. Pages and pages of lore where you can't tell if they are being serious, over the top, or sarcastic.
But the reason why it is called 40K is because Warhammer was made first, and Warhammer 40k originated an expansion to the Warhammer setting set in the future, but became just as popular on its own.