I would totally be inclined to agree if the D&D forums were inundated with people arguing over what it would be like to live for a thousand years. Or what it would be like to have the soul of a demon. Or what it must be like to be part dragon (or whatever Dragonborn are supposed to be).
All I see is lots and lots of discussion as to what cool mechanical bonuses each race should or shouldn't get and which ones are cooler or more effective.
Humans in funny hats, nothing more. Also, humans can be 8ft tall or 3ft tall, so there!
I apologize for the small essay, but at this point it's a response to the general thread.
You joke about the Human height thing, but I'll take it seriously- coming from a culture where everyone has some sort of significantly different feature changes things up compared to being a single anomaly in Human Society. "Why play Tiefling if you were born a human with horns and a tail!" Races and their cultures add up to things that cannot generally be attributed to humans. See: Gith, Tortle, Warforged, etc.
I don't see why forums would need to really bring up the realistic implications of lore, at least not to the extent of Gameplay discussions- lore vids on YouTube haul massive views, and personal character story seems like something handled most by players on their own. There's more questions to ask about builds to the community then there is about making up a personal story. And from what I've seen, anyone that plays an obscure race brings with them SOME relevant role play stuff- that is to say, they aren't playing the same as they would as a Human. Wouldn't all humanoid races have some fundamental behavior stuff in common, anyway? Wouldn't that support the idea that all races have something in common, rather than the rest ripping off Human?
And for the record, even a Human character is just another hat being worn by the human player. It's the one that pushes the fewest boundaries and provides the least varied RP experience, because anything you can explore there is roughly possible with any of the others on top of their individual quirks. There's nothing inherently more valuable or reasonable in regards to choosing Human, Elf or Dwarf than Tortle, Warforged or Tiefling. That does make me curious though- is there a reason that the "normal races" are supposed to be more appealing?
To sum up, I think dismissing the value of alternate races because of some arbitrary Human-centrism in DnD writing is not right. Every character (or character race) is a silly hat, a vehicle for mechanics, prone to misuse by some population, theoretically the same as the others, etc. If you're gonna say it about some, at least acknowledge it's the same for all. "Humans in funny hats and NOTHING MORE" is dismissive without due cause.
I can respect folk who want a consistent setting and such, but anyone who's taking a stance against build-based players, or "obscure" races for being obscure, just seems so... un-fun. It's fine if it's not to your taste for X reasons, but taste should not lead to proclamations of objective value.