a) ripping things off and changing them slightly is the basis of every idea humans have ever had. It's all we do, even outside literary/creative licence. (Wings stolen from birds, wheels taken from watching things roll down hills etc.)
B) in a game of collective make-believe it is a lot easier to describe something as not-X rather than having a novel everyone needs to read for collective back story.
C) you don't know people are ripping off stereotypes or misconceptions. I made a not!Aztecs cultural group by deviating on the actual historical Nahuatl language, culture and political formations.
D) fuck you and your no fun allowed attitude.
E) Every piece of shitty bog dirt can become a diamond if you squeeze it hard enough.