This meme was made WAY before the current LOTR adaptation. But if you want to know why people generally dislike the "diversity" that these adaptations, namely The Witcher and LOTR are getting, is because in their source material, they are in set in ancient or medieval European soil. Although a fantasy, that would mean that the characters in it should be ethnic Europeans, unless stated otherwise.

The Haradims are the one race that is indeed described as being dark-skinned. Just by going through a wiki check on the wiki

"The Haradrim were bold and grim men, fierce in despair. They were tall and dark-skinned with black hair and dark eyes, and for that they were called Swertings or Swarthy Men. The men of Near Harad were brown-skinned, with black hair and dark eyes, while the race known as "half-trolls" out of Far Harad had black skin.[3]"

In the films these guys are all covered up by cloth and have barely any screentime. I think they were based on generally North African-Moor tribes. For them to be labeled as" swarthy men" is by itself an implication that it's something that makes them stand out from other races