From the Sword Coast Adventurer's Guide, emphasis added.
Humans dwell in every corner of Toril and encompass a full range of cultures and ethnicities. Along the Sword Coast and across the North, humans are the most pervasive of the races and in many places the most dominant. Their cultural and societal makeup runs the gamut, from the cosmopolitan folk who reside in great cities such as Baldur’s Gate and Waterdeep to the barbarians who rage throughout the Savage Frontier.
That guide goes on to detail a number of ethnic origins which "are significant minorities in regions or nations that border the North", many of which have dark skin.
So
everything else aside, this complaint isn't even consistent with the source material.