When the more puerile culture of The September that Never Ended happened, we saw most of this machismo garbage take hold. Myself, having access to AoL for a time, saw what that place was like and agreed it was a seething cesspool. Sexist, racist, homophobic diatribes were *everywhere* on AoL. Most heated arguments you'd get on the internet proper were the gnu vs bsd, or vi vs emacs.
Prior to that infamous date, either the custom was Mr. or Sir, or the like. Or, more commonly, was whatever nickname you chose for yourself. Some names have a more feminine sound, while others had more masculine. Yet more were androgynous. Yet when AoL decided to become the gateway to the internet, is when we saw that "average" (aka: racist, sexist, homophobic, different-phobic) people join for the first time, the old guard of the internet didn't know how to handle it - we've always dealt with a higher class of people, and these distinctly weren't it.
It really didn't start turning really bad until these Web 2.0 companies started linking payment gateways to real names. Overnight, your account would be locked/banned for "fake names or transgender names"... And companies like Facebook would use your friends as that proof. And of course, we know how all that is turning out - it's just as unsafe for women (or really anyone "different") walking on a sidewalk as it is with their real name online.
Fortunately, there's still fringes on the internet. I don't know if you're male, female, young, old, disabled, ,black, white, native, asian, from a different country, etc.... If we leave it out of the discussion, its unimportant. HN is most definitely not one of those areas, as the assumption is that you're a white, probably male, tech worker, and that you're happy with venture capital and startups.
(I really don't want to mention those quieter areas, as it reminds us of our old ideas of the internet and all the wonders we imagined it could do... Unlike today's marketing hell, capitalistic cesspool, and emotional monetization. It doesn't have to be like that.)