Um...yeah. I actually talk about that in the blog post.Well reasoned blog entry. I understand your POV but don't agree with you. Roland is only iconic to Constant Readers. Joe Public has no idea who Roland is.
Run through the DT story in your mind. Now change Roland's race. Switch genders. Run through the story again. Does changing any of those characteristics fundamentally change Roland's journey? I From where I stand, the answer is no.
Change Roland's race and you have to change multiple things about Susannah, including Detta's entire motivation against Roland. Among other things.
One thing I didn't point out is that if all Gunslingers are descendants of Arthur Eld, that means every Gunslinger portrayed had better be black.
Also, I'm not talking about Joe Public. I'm talking about Constant Readers. Any time there's an adaptation, the goal should be to entice people who've read the original. They'll bring their friends. Word of mouth will spread from them. But if they hate it, you lose all that.