wait... wait wait wait wait..
Are you actually making a lore argument why the game SHOULD, not has regrettably, but SHOULD only have recolour Humans as races?
In the sense that you would be AGAINST having lets say Dragonborn or Warforged (two races we have evidence for)?
You have to start an argument strong. What kind of argument starts with "Well yes we should not have cool and different things"
The lore has rules. Not just humans, by the way, also elves, drow, tieflings, aasimar, githyanki, githzerai, grimlocks, gnolls, human-sized goblinoids, orcs and even dragonborn, if they add dragonborn to the game that is. I can assume your dragonborn would be the first one taken to be implanted with a tadpole, as dragonborn originally came from Abeir, and I made it clear that mind flayers will experiment ceremorphosis on races they have never encountered before.
As I said before, the Forgotten Realms lore has rules,
not everything is along the lines of "Anything Goes". However,
the rules can be bent, as I pointed out that the ceremorphosis process can be warped to work on halflings, dwarves and other short heighted races, but the rules CANNOT BE BROKEN.
