[Note: This is from a comment GRRM made at "Not a Blog" discussing casting on Game of Thrones.]
I hear what you're saying, and I appreciate knowing your thoughts and feelings on these issues, which you've stated very eloquently.
No one meant to break your heart or crush your soul, certainly. There are a number of complicated issues involved here, and I don't have the time or the energy to address them all. ((Might make for an interesting discussion at a con, if we had a hour or two and a good cross-sample of people of good will and differing viewpoints)).
I understand that Salladhor Saan and Missandei and Xaro Xhoan Daxos are not major characters, certainly... but it does trouble me to have them dismissed as "otherized supports to... white PoV characters." Yes, they are supporting characters; they're not protagonists, they don't have chapters from their own viewpoint. But Oberyn Martell is a supporting character as well. Which is not to say he is unimportant. Robb Stark never had a viewpoint chapter either.
I try to make ALL my characters fully-fleshed and human, whether they are secondary or tertiary characters, minor players, or spearcarriers who only have one line. I grant you, I may not always succeed, given that I have literally thousands of characters, but the intent is there. I should also point out that I am not done writing the books. If you've read my novels, you'll know that sometimes a character who seems very minor in one book assumes great importance in later volumes... and sometimes even becomes a POV. Let me hasten to add, this does not mean I am promising to make Salladhor Saan a POV character... but it does mean I am not done with him. (Of course, in the books Saan is white, a Lyseni of Valyrian descent, so that may not help much).
Speaking of Valyria... right from the start I wanted the Targaryens, and by extension the Valryians from whom they were descended, to be a race apart, with distinctive features that set them apart from the rest of Westeros, and helped explain their obsession with the purity of their blood. To do this, I made a conventional 'high fantasy' choice, and gave them silver-gold hair, purple and violet eyes, fine chiseled aristocratic features. That worked well enough, at least in the books (on the show, less so).
But in recent years, it has occured to me from time to time that it might have made for an interesting twist if instead I had made the dragonlords of Valyria... and therefore the Targaryens... black. Maybe I could have kept the silver hair too, though... no, that comes too close to 'dark elf' territory, but still... if I'd had dark-skinned dragonlords invade and conquer and dominate a largely white Westeros... though that choice would have brought its own perils. The Targaryens have not all been heroic, after all... some of them have been monsters, madmen, so...
Well, it's all moot. The idea came to me about twenty years too late.
In any case... I hope no one heaps any vitriol on you for stating your views. I may not agree with all you've said, but I respect where you've coming from, and you've been nothing but polite. You do not deserve abuse for that, and if anyone tries to heap some on you here I will delete their posts (I have no control over what happens elsewhere, alas, but I can at least keep my own blog civil).
FWIW, though, I do not think David, Dan, HBO, Nine Gold deserve the vitriol being heaped upon them elsewhere on the internet either (NOT in your post, let me stress). And I especially don't like to see poor Pedro Pascal getting abused, before he's even delivered a line. By all reports he is a terrific actor who gave a great reading at his audition. THAT's why he got the role.