7. I don't know about that fandom in particular, so I can't say anything about its quality.

But I don't see how it's a double-standard, honestly. Some fandoms change mythology and get away with it, because the final product is good. Some fandoms change mythology and end up with something that sucks. It's the same with book-to-movie adaptations: some are good, some are bad, some are blah.

So no, I don't think I have a double-standard because I like many different versions of the Arthurian myth and still hate Saint Seiya.

(edited to fix a spellnig mistake)