I think this is the real distinction:
All Myths Are True: Fantasy creatures are explicitly stated to be believed to be a myth In-Universe. They are then revealed to all be real but hiding under The Masquerade the whole time.
Fantasy Kitchen Sink: Throw everything from fantasy in a pot and don't hide it. All the fantasy elements are out in the open from the start.
edited 26th Feb '13 3:09:51 PM by shimaspawn
Reality is that, which when you stop believing in it, doesn't go away.
-Philip K. Dick
It could be a little more complicated - fantasy is a bit broader than myth is, and there might be other reasons besides The Masquerade that explain why mythical beings aren't public knowledge - but overall I think that seems to be a pretty good distinction.
I just want to point out that one of the reasons for the "misuse" is probably the laconic saying that the trope is when "all mythologies mentioned in the work are based on real people and events." It sounds like the trope is when Real Life myths are used in the work, which this discussion is saying is not what the trope actually is.
I do like that laconic, though: "There are myths and legends in the setting and they are real" In-Universe.
Firstly, I disagree that the second is a clone of Fantasy Kitchen Sink due to the differences between fantasy versus mythology and folklore mentioned previously. Secondly, though, how would it be trope decay?
Yes, there is a difference between fantasy and folklore/mythology. ButFantasy Kitchen Sink refers to a slue of common elements of fantasy commonly thrown into various settings all of which are in some way based off of folklore/mythology.
It would be trope decay because, as I explained previously, The Masquerade is a completely different trope. Saying the trope is when a Masquerade is involved would be redefining All Myths Are True — exactly what trope decay is.
I'm a believer that ambiguity is worse than verbosity. The laconic is where people go to get a quick understanding without actually reading the article. The laconic is the last place there should be ambiguity.