Whatever the case, they're making their voices heard. And it's one thing to disagree on people having problems with Black Dwarves, it's another to blanketly assume they're all against diversity.
In most cases, people are fine with it where it makes sense and fits. It's when things don't fit when people start being vocal.
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If they were really interested on defending diversity, all they need to do is sinoly ask if people think a diverse cast would be acceptable and how they think it could work. Simple as that
Instead it seems there's a lot of projection going on where they believe anyone who isn't for Black Dwarves must be neo-nazis or something. It's very disconcerting.
I think most people have more common ground than it seems. Like, most people here will probably agree that the Peter Jackson movies were good and respects the source material even with all its creative liberties. And regardless of what diverging opinions exist towards RoP, I think most people would want it to have the same level of respect to the source material as the PJ films had. Creative liberties are fine as long as they're within reason and make sense.