Allowable words
One might guess that Philipp is white. As far as I know, he (gender inferred from name) is from Germany, which has a small minority population. He probably speaks English as a second language.
It is quite possible that he is not familiar with the difference between the words (at least one of which can be offensive, so read behind the spoiler tag at your own risk)
Negro and nigger.
These words share a lot, four letters out of five or six.
There was a time when the first word was mainstream, the way that African-American is today. For example, see this organization, which is run by and for African-Americans.
Of course, even given all that, it's hard for a white person to say that a particular word is all right over a black person's objection. That the word was being used by a black person doesn't fix it.
The second answer
That said, I would tend to agree that the second posting of the answer, which started
Don't ask about black people if you do not want answers from black people. Or, specify at the question that you only want answers from white people.
was overly hostile and perhaps misdirected. I would be fine with deleting that based on the existence of the first answer, the hostile tone, and its misdirection to be justified.
Why misdirected? Because it seems far more likely that the kind of person complaining about "negro" and "black students suckle on the teat of western academia" is either black or claiming that it would be offensive to black people. And it seems unlikely that Philipp just happened to pick that answer to review. It seems more likely that there was a flag.
Deleting the second posting of the answer was correct in my mind, even if the first deletion was not. That's not how we resolve things here. The correct way to get the answer restored is a meta question.
Selective enforcement
There is also a bit of a problem with allowing certain language by black people and not white people. For one thing, we don't know who is black and who is white here. If a white supremacist came here and posted about the difficulty of being black in the US, we can't really tell the difference from a black person doing the same thing.
Beyond that, even if we could prove blackness, it sets a bad precedent to allow one person to use language that we would not accept from another person. Because then when someone else uses the same language, how do we say that it is now off limits? We should have one standard for posts, not a different standard for each demographic group.
There may be some reason for an exception in certain cases because it is clearly necessary. For example, the text that I put behind spoiler tags is important to the post. Without it, I could just as well be talking about nitro and mentor.
At least the first particular word choice was not necessary. Either black or African-American could be substituted for the one word without loss of understandability.
The phrase
black students suckle on the teat of western academia
is harder to replace, as it carried actual meaning and many replacements would be offensive because of that meaning.
Authenticity
From a comment:
It's possible that it was a non-black troll pretending to be black, but I think that the point of view is one actually held by the poster, because it's too weird to fake.
This point of view is more mainstream than it might first seem. This is essentially the Malcolm X view. Malcolm X wasn't bothered by the concept of "separate but equal" but by the implementation. He argued that it was not in fact equal, only separate. He would have maintained the separation, but in return he wanted a real separation. Black people would have their own place to live under their own laws and would not be subject to white law. Something more like Native American reservations. From the Wikipedia link:
While the civil rights movement fought against racial segregation, Malcolm X advocated the complete separation of African Americans from whites. He proposed that African Americans should return to Africa and that, in the interim, a separate country for black people in America should be created.
It is possible that his views had mellowed later in life, when he was using the name el-Hajj Malik el-Shabazz.
It remains possible that this was a fake, a white supremacist or a Russian rabble rouser pretending to be a black separatist. But it's also possible that this was just what it seemed, a post by a black person with heterodox/non-stereotypical views.
Whitesplainin'
I'm a bit troubled by
(The answer by guest271314 seems to have argued that the Academic version of '50s US School Desegregation resulted in a general overvaluation of blander mainstream scholarship and with it a corresponding but unmerited deprecation of segregated scholarship.)
This seems to be a whitewash (see what I did there?) of the original post, which argued that school desegregation led to black children being predominantly taught by white teachers. This increases alienation, as it produces weird white explanations like "blander mainstream scholarship" that seem to miss the point.
I don't want to get too much into that, as two white people arguing over what a black person meant is itself a microaggression. Presumably the black person is better capable of clarifying what was meant than we are. But until that, I didn't want to leave so egregious a rewriting unchallenged.
Original, potentially offensive, first paragraph for those who want to consider for themselves whose interpretation is closer:
Some black people consider Brown v. Board of Education of Topeka, 347 U.S. 483 (1954) to be the worst decision as to Negro education that ever occurred, the reason being that Negro children would no longer being educated by Negro teachers from a Negro perspective, but would instead by educated by white teachers from a white perspective.
black students off of the teat of western academia
is not a racist comment. Even if the context suggests otherwise.