I don't read everything in these forums, so you might be seeing something that I'm not. I don't see that disagreement is labeled as "trolling" or "disruptive" or "anti-inclusive." I think that dismissiveness is.
Disagreement and dismissiveness seem to be somewhat of a spectrum, and a matter of interpretation. Plus, I think most of what you call "dismissive" is not dismissing the problem of actual racism, but disagreeing with an interpretation on what constitutes racism.
So I'm not sure how one can disagree without it being interpreted by some as dismissive.
Whereas what I see happen again and again is that criticism is characterized as outrage -- usually with the point being that the outrage is misplaced, manufactured, out of proportion, or actually sought after by the aggreived. "If you look for problems, you'll find them. Being offended on behalf of someone else. Screaming racist at everyone who disagrees with you." I read these sorts of comments not as earnest disagreement and engagement in the conversation, but as active and intentional marginalization of others' thoughts and concerns and experience.
I don't recall anyone who simply posted "I don't see it" get the sorts of responses you're citing.
But, repeating for emphasis: I don't read everything in these forums, so you might be seeing something that I'm not.
Yeah, I see that, but disagree with your interpretation - at least insofar as such comments being inherently dismissive or disingenuous (aka, trolling). We're in a bind: How can someone voice disagreement without it being seen as dismissive? Meaning, if someone earnestly feels the way you express in that quote, how are they to communicate that? Should they just be quiet and not participate? Should they assume they are in the wrong and seek to learn the proper way to see things, perhaps examine their own defensiveness, even if they don't feel like they're defensive, but assume that they are?
When people say "I don't see it," what usually happens is that those who "see it" see it as an opportunity to educate them, and if they continue not to see it (that is, disagree with the interpretation), they're labeled as anti-inclusive or dismissive, or condescendingly as "not ready to see yet." What if someone can see and understand the interpretation, but just disagrees with it?
Meaning, I'm pointing to a problem of underlying intolerance for different viewpoints. An us vs. them mentality that I think does great harm and prevents actual understanding of different viewpoints and sows further division. I'm advocating for greater tolerance of different viewpoints - not of actual bigoted ones, mind you - and not assuming that "if you don't see things as I do, that X, Y, and Z are racist, then you're dismissive or racist yourself." It is a kind of intolerance and division that is poisoning our culture, including the RPG community.
And just to be clear, I do think that some on "the other side" hav their problems too, mainly having to do with diminishing the prevalence of systemic bigotry and the lived experience of those who have experienced prejudice. Not everyone who disagrees with every outcry of racism, maybe not even most, but some. But again, not seeing the depiction of the hadozee as racist (for example) doesn't mean one dismisses the experience of another.