I think in the context of gaming and the Internet, and indeed nerd culture, it goes into a specific viewpoint that social identity itself is a problem because it is the catalyst for bigotry (not the people that engage in bigotry over something as benign as social identity, of course), which can at times feel similar to a lot of the bullying middle class teens have gone through (not to say teens cannot be victims of bigotry), and thus anonymity is the way to go because then everyone is a blank slate, free of the pre-existing assumptions associated with any identity, who succeeds or fails on their own merits as a contributor to the community. You see it in 4chan's whole worldview and structure, fandoms that pride themselves on "unity" and being a "big happy family" over "drama," and to a lesser extent within the wider Internet community and it's desire to keep as much anonymity as possible.
However, anonymity as an ultimate good is a terrible basis for a social worldview because everyone who uses a computer or engages in some other way with nerd culture is ultimately a human being already built with preconceived notions about others' identities and a general idea of the self and its given identities. So one's Internet history and habits are going to be an approximate reflection of their "real life" self- Google wouldn't be able to advertise to you otherwise- and thus the many parts of the Internet have take on aspects of the current dominant worldview- the one of straight white men's and the associated privilege of being able to actually believe in meritocratic ideals.
So then here comes a person who sees this, or has some interaction with a person where they're assumed to be something they're not, or they meet someone who's like them in some way. This person then declares themselves to be a woman, or a black man, or gay, or some other aberration from the "anonymous," default, colorblind bubble of the Internet. The
very declaration of these identities is an inherent attack on Internet culture, because you're now subsequently introducing the societal baggage that has come with the history of these identities back into the "anonymous" bubble, the societal baggage that people who subscribe hard to anonymity tried to solve by just ignoring it and assuming you were a "blank slate" straight white male in the first place.
It's why people get pissed at "putting politics into games" through the use of social identity while not caring about the politics of WWII. It's why people tell minorities to make their own games instead of trying to inject their presence where it doesn't belong. It's why people keep trying to lambast Anita Sarkeesian as a no-good lying outsider while her harassers are minimally targeted with these same kind of offense tactics. Identity is a reminder of the real world, and nerds don't want to deal with the real world because they might be forced to confront some nasty things about their character, even when they're calling you a nigger in Overwatch.
tl:dr--
Listen to Foldy. He's already broken this shit down in an amazing way.