It's literally the Paradox of Tolerance at play. Contrast Twitter with its "free speech alternatives" and then consider that Twitter is actually historically intentionally hands-off when it comes to content moderation.

I agree that an "HN for women" likely wouldn't solve any of these problems as by that description alone it sounds like the "girlboss feminism" equivalent and would likely inherit many of its problems. But I would also argue that if you try to distill the problematic aspects out of HN it ceases to be HN and you should really just ask about more inclusive tech news communities rather than a pinker version of the orange site.