The problem I have is that you seem to set at zero the other set of concerns here—the ones I described at the top—intellectual curiosity and civil, substantive conversation. Those things are the raison d'etre of this site. Do you think I'm wrong that political flamewars don't threaten them? Or that they don't matter?
I understand why a politically committed person might say "screw those values, the cause is too important", but that amounts to a scorched earth approach that doesn't see this place as much worth protecting and can easily progress to other battlefields for further scorching. My job is to make sure this place doesn't burn, so it's hard to take advice from that quarter. I'm all for suggestions about how better to serve the site's values—and by the way, 'civil' includes being welcoming to others—but objections that don't think they matter are harder to credit. It's pretty easy to say what we should do if you don't share our goals; not so easy to struggle with the tradeoffs if you do.
It's my view that for all its flaws, this community has something worth protecting. Perhaps it only lives up to 40% of its values, but that's still a lot, and it's the reason why people are attracted here to talk about things, some of which are inevitably political, in the first place. If you think significantly better is possible on the open internet, show me where; from what I've seen, everyplace else is so much worse that this one is clearly worth protecting, in the hope of achieving better. And if you think we're not interested in welcoming people who suffer from social or political disadvantages, I don't know what to tell you, other than that you'd be misappraising well-wishers. I hear you that it might happen anyway as an unwanted effect, maybe even is happening, and we care about that and take it seriously. But that information tends to come in complex political and ideological packages, and it can be hard, even for a well-wisher, to decipher signal from noise. The discourse around these things tends to be all-or-nothing, indeed extremely so. For us that's a double bind, because HN can't be either.
This is true. However, you can observe here that one side petitions you; the other bullies you. This would be unusual in a genuinely symmetric situation...
So...I can't come up with a better way to put this: do you really think that there are intellectually satisfying, civil discussions to be had when your existence is a matter of debate? Like... 'hga wasn't alone. You know that. He was just an idiot who went straight at it straight instead of hiding behind cites of The Bell Curve, instead of "but why should there be programs for black people or women?". I get your focus on "civil, substantiative conversation" and I respect that, but you gotta know as well as anyone that harm happens behind the "civil, substantiative conversation" of just-asking-questions and oh-it-can't-be-that-bad,-can-it?, the soup of toxic sexism and racism that's all over here over the last year or two. The functional result of "no politics" is that that won't be challenged, not that it'll go away. I agree with 'tptacek when he says that most political comments on HN are alt-right trolls; "hey guys, subtext rather than text" leaves a lot of shadows.
You and I are effectively re-litigating the same arguments that have come up in many other places. What would be awesome and a change of pace would be to learn what HN plans to do to make itself civil and welcoming to underrepresented folks, if that's the ethos you want to have. And you say you do, so I believe you. I mean, hell, I'd love to help out if I can; you have a bigger stake, but you're sure not the only person who thinks there's something worth having here.
(As far as other places on the internet--I have a few that come to mind. Open ones, but not ones on which I want to sic the jerkier part of HN just to prove a point in an argument. Shoot me an email if you're curious.)
One side wants to exist. The other side wants the other to stop existing. It's about as symmetric as lions and buffaloes, although a buffalo will kill a careless lion now and then...