Ever noticed how easy it is to play an Elven character in D&D? It's a template you're familiar with, you know how they work, you've had plenty of exposure to them.
I'm trying to point out how pointless it is to have a stick up one's bum as to X being more legit. That people accept that these things don't exist, and that no-one's picture of them is the legit one, was my main point. My other point was that this attitude exists to the point of being super-excessive.
I'm not saying that fantasy races should not be humans with different "hats", often differing less in habit than real human cultures do. I'm not even arguing against some hats being common. I do find it pathetic that elfs and such seem to differ as much in fantasy as Klingons do between the original Star Trek and the The Next Generation.
Consider this: Cute, albino 'dwarves' calling themselves 'okknu' who wear dwarven/okknan sunglasses and value hair because they have so little natural protection from the sun. Not like human albinism, as their bodies are designed around not having pigment rather than it being an unexpected thing that breaks much more than sun-resistance. That is probably the most different dwarf concept you will ever hear despite easily fitting in two sentences, one of which being only a clarification. I even made the one psychological thing, valuing long hair, to just be a different take on a trait of the standard fantasy dwarf. I refuse to believe that would be different enough to cause significant role-playing problems.
I'm not trying to take away your D&D elves, man. Just don't insist that D&D elves are the only
true elves for all of fantasy, and we are cool.