Science fiction used to be a Fortress of Solitude for sad little white guys to play Dungeons and Dragons with each other and not feel bad that they had no lives at all and could never get laid.
I’m with you, but that was some excessive D&D nerd hate you opened with. If you consider one of the inventors of the game played it with his kids, and one of them was his daughter, it kind of, ahem, dispels the notion that the guy wasn’t getting laid or that only guys were playing it.
That said, gaming culture, which is a cousin to sci-fi culture, still remains highly male-centric. Even as I write this, the 2017 WSOP is underway and, yet again, no women are present at the final table. It’s not for some nonsense reason like women are bad at poker, but because only a tiny fraction of the entrants were women. Just like every year before, but the disparity is slowly eroding.
Compared to poker or video gaming or Magic: The Gathering, D&D is probably among the most welcoming and inclusive gaming environments for women, whereas the “cooler,” more socially-accepted video game culture is a bastion of bro misogyny. That’s not to say D&D or other types of tabletop gaming are remotely close to perfect, but it’s ahead of the curve, and probably doesn’t deserve to stand in as an icon for an odious brand of white nerdism. People should, instead, look to it to see the progressive changes it has made within the structure and rules of the game itself, and how women (including women of color) have risen to positions of authority and expertise within the community. D&D nerds don’t seem to rage about that compared to sci-fi nerds who have trouble accepting Doctor Who being a woman.
It’s also worth pointing out that modern day sci-fi shows like Dark Matter and Continuum, while they lack the cultural cachet of a Doctor Who, have been chugging along with female leads for years now. Star Trek: Voyager went seven seasons with a female lead. It suggests that Whovian ire about a female Doctor Who is at least somewhat anachronistic, and the QQ surrounding it does not reflect how the broader sci-fi audience was ready for a Wonder Woman movie 10 or 20 years ago, and has no trouble accepting a female Doctor Who.