The same can be said by making it conform to a grey theme, except doing so also makes certain aspects of the setting make less sense. The Light and the Dark are the biggest example of duality in the setting, but detaching good and evil from them only begs the question of "Why of all concepts are those two the only ones not affiliated with the Force?" Another question is "Why, if the Light Side brainwashes people like the Dark Side does, do we have so many mountains of more people falling to the Dark Side than falling to the Light?" Or, finally, "If the Dark Side isn't really any more evil than the Light Side, why are 99.9999999% of its users massively evil bastards and a massive majority of Light Side users are, at worst, flawed heroes?"
Black and white is what gets us things like the original trilogy. It was a great series of films, and to think that greatness is held back rather than enabled by black and white morality is wrong. It was only through that non-grey theme that we got the originals, and from it we can get other great stories.
You assume shades of grey implies equivalency. No one is saying Sith and Jedi are morally equal. No one is saying the Light side is objectively as bad as the Dark Side.
What people rail against is the idea of turning the platonic ideal of life itself into some absurdly stark dualistic system. The idea that all hate, all anger, all passion, all fear,
all attachment! leads to wickedness and suffering (all while touting itself as holistically expressing life) is something people tend to reject because it's fundamentally at odds with their worldview and experiences. When one simply wants to paint a heroic tale of good triumphing over evil like LOTRs or the movies themselves, that's fine. But at it's core, Star wars is an entire setting- a rich and varied universe where such a moral simplification fails to do justice to it.
Case in point-the Jedi ideology espoused in the movies is one bereft of sympathy and empathy. Where Jedi are supposed to avoid attachment and thus avoid suffering. Sympathy is the notion of sorrow for what happened to another, empathy is the understanding of another through attachment. Even the Jedi we see fail to truly hold themselves to what's a fairly impossible ideal.
People don't like Revan just because he's one of the less objectively evil sith. It's because he helps posit the idea there
are some things worth hating, some things people should feel passionate about, some things people should be angry over. When he witnessed genocide, he moved the galaxy to stop it. And then when he saw the threat the galaxy faced he went to war to save it. Because he did a lot of bad things, got a lot of people killed, and in general was a villain- but looking at his deeds you couldn't call him objectively evil or that his motives weren't sympathetic even until the end.
People like Kreia (I personally don't) not because she espouses that the Light and Dark side are the same or that the force is misunderstood, but because she had the radical idea that life should be allowed to live and grow on it's own terms and merits. 'No gods, no masters, only men' so to speak. An idea of self determination is something
anyone can understand.
People like the Jedi Lords because they took the teachings of the Jedi, and combined them with the simple act of immersing themselves and integrating themselves into the galaxy. That they refused to let the tenets of the Jedi prevent them from simply
living, while at the same time using those same tenets as a way of living and making better lives for others.
I respect George Lucas for creating Star Wars, and I enjoy canon while acknowledging Legends is often a clusterfuck of hundreds of incompatible plots. But at the same time, Star Wars has grown beyond Lucas' vision, and I frankly don't give a damn what he feels Star Wars should or shouldn't be by this point- it's bigger than him. Anyone who insist that Star Wars is 'supposed' to be a setting of moral absolutes can kindly go fuck themselves, because at this point Star Wars is so much
more than a collection of movies with cartoon series supporting them- and anyone who insists on arbitrary labels to debate it can kindly go fuck themselves.