I think the comment was very reasonable. Yes, it mentions gender/ethnicity/nationality in a way that is likely to incite some people to attack, but in this case gender and ethnicity/nationality was mentioned in the article as a relevant detail, so I think it's reasonable to include it in a comment.
I just feel that it's not reasonable to hold GP responsible for a touchy subject, when the touchy subject is part of the article they're commenting on in the first place. If it came out of nowhere, then obviously that'd be a different story.
Btw, I don't think it's quite true to say that the touchy subject was part of the article. Even if it were, though, the burden is on commenters not to take an HN thread further into flamewar. This is in the site guidelines:
"Comments should get more thoughtful and substantive, not less, as a topic gets more divisive."
"Eschew flamebait. Don't introduce flamewar topics unless you have something genuinely new to say. Avoid unrelated controversies and generic tangents."
1) They clearly didn't intend to incite people to attack, and
2) How much responsibility are you really going to lay at their feet for that? If I say in a comment, "yes, we really need to do better at fighting climate change", there will absolutely be some people who will take that as an opportunity to start a flamewar. Some topics are controversial enough to where fairly innocuous statements might get people flaming -- is discouraging the innocuous statements really the right move? You're essentially saying that it's each commenter's job not to offend people, even if the offended parties are being unreasonable. That effectively hands a subject-matter banhammer to them.
I don't entirely disagree with what you're saying about expected value of the subthread, I just think that there's a line there, and in this case the GP stayed well on the right side of it.
I don't think there's much point trying to agree on every case, only on the principles, since different people will always call different cases differently. From my perspective, the comment wasn't innocuous. It clearly steps away from the specifics of the OP's story into generic ideological themes. Asking HN commenters not to do that is standard HN moderation (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...). It did that repeatedly (though subtly, because it superficially takes the form of a friendly congratulation) in a way that was bound to land as flamebait in the thread. When a friendly congratulation comes with a political agenda, the political agenda will forever be the high-order bit.
"You will still face difficulties because of your gender and ethnicity" seems particularly subject-changing, and also patronizing, since it replaces the author's specific story of her own experience with a generic story based on different filters. We can't know and shouldn't presume to tell her what her future experiences will be.
I feel bad spelling this out because it makes the GP comment sound worse than it was—it doesn't deserve an exhaustive critique. But when people question what I posted, I feel obliged to share my thought process. Which requires figuring out what it was, since a lot of it by now is instinctive pattern-matching.
I was definitely not trying to introduce an agenda. I will admit I was a bit naive about how my words were going to be taken by some (really just a couple people who took my comment in the _worst_ possible light, in my opinion). I really just wanted to thank her for being part of a positive change in society and encourage her to continue.
The specific comment I made about gender/ethnicity seemed to me like an obvious given, not some prophetic word. The article implied this struggle quite clearly, I thought, as well as the tone of the the OP's other comments in this discussion.
I think given how things actually did play out that dang's actions were totally fine here. As a result I'll try and be more conscious of my words, because I don't want to be a part of a flame war anyway. I try to avoid sarcasm and destructive criticism in general. My history on this site shows that, I think.
I’m sincerely sorry. I didn’t realize that the mere mention of gender and ethnic discrimination being a problem in general was all that controversial. I was hoping to be a source of encouragement for OP, but seeing how people responded I understand and appreciate you stepping in. I know keeping a community civil is an important and difficult task, so thanks for all you do dang :)
It stepped noticeably away from the specifics of the article and noticeably into generic flamewar topics. Other commenters predictably responded in kind, just with more indignation and lower-quality comments. This is how flamewars get started and it's clearly traceable to this root. If you want more explanation, I've written more in a sibling (cousin?) comment here: https://news.ycombinator.com/item?id=26255991
The general principles are repeated (ad nauseum, I'm afraid) here:
https://news.ycombinator.com/newsguidelines.html