Here's the thing though: nobody has to agree 4chan is the hero of the story. It's also reasonable to look at 4chan and say "Gross and legally correct is still gross" and let them soldier on alone.
You'll note the "First they came for" poem has a beginning and doesn't extend to all subcultures. It doesn't say "First they came for the KKK." And, of course, it doesn't say "First they came for the Nazis."
The original German of the poem does say, at the final line, "Als sie mich holten, gab es keinen mehr, der protestieren konnte." That is, "When they came for me, there was no one left who could protest."
So, yes, the poem does extend to all subcultures because it reaches out to include every voice of opposition to totalitarianism, until no one is left but the speaker.
It's also meant to be understood in the first four lines: The people mentioned — communists, trade unionists, social democrats, and Jews — were meant to be emblematic of people who are seen as enemies or outsiders to the author's cause. These are people whose values are seen to be radically different than our own.
Remember the context: the author of the speech, which was re-rendered as a poem, was a real person, Martin Niemöller, who was a pastor in the Confessing Church, which was an underground church movement organized in resistance to the Nazis.
However his speech, given in January of 1946, was an indictment of the Confessing Church. The movement was initially organized primarily as a form of resistance to governmental interference in religion, rather than to speak out for all people. Niemöller was, in fact, explicit that this was about people who were his "opponents" and his "enemies":
> "... The people who were put in the camps then were Communists. Who cared about them? We knew it, it was printed in the newspapers. Who raised their voice, maybe the Confessing Church? We thought: Communists, those opponents of religion, those enemies of Christians—"should I be my brother's keeper?"
Instead, Niemöller points out, in a theologically poignant allusion to the story of Cain and Abel in Genesis 4, that we have a responsibility to our fellow humans to look out for their wellbeing and their interests as our own.
So yes, that poem calls for you to look out for the wellbeing and interests — including freedom from oppression and censorship — for those folks who you might now perceive to be your enemies.
See:
https://en.wikipedia.org/wiki/First_They_Came
It should be noted that Niemöller was not the only one to draw on this story as an indictment of the church's inaction. Margarete “Marga” Meusel, a contemporary and correspondent of Niemöller wrote this in 1935 which was antecedent in the body of thought informing the 1946 speech:
> Why does the church do nothing? Why does it allow unspeakable injustice to occur? ... What shall we one day answer to the question, where is thy brother Abel? The only answer that will be left to us, as well as to the Confessing Church, is the answer of Cain. ("Am I my brother's keeper?" Genesis 4:9)
> You'll note the "First they came for" poem has a beginning and doesn't extend to all subcultures.
Just as saints and captains of industry deserve no less scrutiny and liability under the law than the rest of us, scoundrels and horrible people deserve no less protection under the law than the rest of us.
If your disgust for an entity prevents you from being able to recognize when they're doing something that's an unalloyed good, then you still have quite a bit of emotional maturity to develop.
To put the previous paragraph another way: It's entirely consistent to decry an someone as a loathsome scumbag that all upstanding people should shun and refuse to associate with while also remarking that that one time they dove into a freezing river to save a child being swept away was a good and noble thing to do, and behavior that we should all aspire to mirror.