Everyone here is a dumbfuck?

I feel you're making the mistake of viewing this as a left-versus-right sort of thing or something similar. Notice they didn't say "Republicans" in the post (although of course it's possible they mean it) or something like that. I can't say what OP will say in the future but as currently stood their post merely addressed racists as racists, etc.

So there's not (presently) any burden of proof here regarding whether or not a certain group meets these descriptions. Therefore in this context we're simply talking about straight up, definitive racists, etc. regardless of anything else about them. Surely you wouldn't then insinuate these people should simply be overlooked, perhaps heard out.

"You just identify with them because you feel oppressed in life yourself."

I can't speak for OP but that's a deeply troubling assumption. Why reach that conclusion? Must one fear rape to have a problem with rapists? That takes us to the next common assumption besides personal oppression, virtue signaling.

I'm a straight, white, cis male, so I'm not exactly oppressed, at least no more than anyone is (we all are), and I feel deeply for the victims of all of these issues. Anyone who finds that (even remotely) hard to believe has said way more about their own personality than mine. It's incredibly revealing when people cry "virtue signaling" and the like in response to criticism of xenophobia. If I say I'm against rape I'm not virtue signaling. If I say I'm against the human trafficking of children I'm not virtue signaling. If I say I'm against animal cruelty... oh wait. Uh oh. Lines are already blurring. Maybe virtue signaling? Homophobia, definitely virtue signaling.

I've went over it and over it in my mind and sadly the only thing I can think of is that it's where their own empathy begins to drop off. It's where the issues begin to become non-issues to them regardless of what they say. If it's not, then why have I never once been accused of it when discussing human trafficking? Why am I not just trying to look like a fantastic guy? Is it because we just assume everyone should have a problem with that and don't do the same with these issues because they're... just not that big of a deal? It is. It is what it is and it's fucking sad. These people look at someone who says they have a big problem with racism, sexism, homophobia, transphobia, etc. as if they've just said, "I just donated half of my organs to dying children right after I sold all my possessions to fund my trip in which I personally rescued 200 polar bears."

Not being a xenophobic asshole isn't worthy of a damn gold medal! It's not far from the bare fucking minimum you can ask of a person in modern society. Are we virtue signaling because we mention we don't intentionally piss on the floor in public restrooms as well? Is there an award for that? Maybe a gold star sticker that says, "Congratulations on functioning in society."

People like OP don't have to be personally oppressed and they don't have to be trying to impress anyone either. They just care about issues that leave us feeling mind-boggled as to how others wouldn't also care. I feel that their very understandable anger makes the still-harsh words they have said appear harsher on the surface than they really are. Notice they actually haven't wished a premature death on anyone. They've simply made the mistake of assuming these problems will all but vanish with the older generations and they're quite ready for that to go ahead and naturally happen.

Personally, I'd prefer these people simply change and keep on trucking with us. Like you said, sometimes they mean well. They're often more motivated by a perpetual cycle of ignorance than malice. But I'm not going to act like there isn't an enormous problem.