Nerd Rage, general hatred of Amazon, and, yes, a certain degree of racism are surely aspects of it for some people, but I think that the backlash against the "Rings of Power" is more prosaic than any of this.
What I think that it boils down to is that "Lord of the Rings" was made with love. Tolkien was certainly not writing it to make huge amounts of money off of it, he did it out of love; the generations of children who grew up RPing Elves and drawing detailed maps of Osgiliath and somehow forcing their way through the text of the Silmarillion were acting out if love; even, yes, the Peter Jackson movies, which were absolutely capitalist enterprises from top to bottom, would not have been what they were without the love of the people working on them.
And then along comes Amazon, for whom this obsession, this passion, this love is just a market segment. Amazon, the economic equivalent of a malignant brain tumour, to which all things are always and only IP to be consumed. And they show complete disregard for the original text, because they just don't care. To them, it's an aesthetic. Something they can market to fans of Game of Thrones or the Witcher. A centrepiece for their own forays into streaming.
So that's the basis for the pushback. It's not because Galadriel has the wrong heraldry or because the Dwarven women are beardless. It is the revolt of culture against being puréed, processed, and packaged into #Content