This essay does not read like an intellectual piece at all. Poorly defined terms, labeling people, non-falsifiable psychoanalysis. And to top it off he calls both labeled groups of people "less than men". All of this setup to deliver the profound advice to just ignore them. (Before people call me a "hater", note that I strictly do not meet the definition, because I like a lot of his essays.)
The pun is that "fanboy" encapsulates "not a man" (boy). Of course the archetypal fanboy or hater is kind of a weakman (if not quite a strawman), but that's the point; it's a model. He's pointing out that in that model, the "boy" is very relevant and indicative.
If he were discussing the word "fangirl", he'd probably say "not a woman" instead, but I think that would result in more flak ("as a mam, who are you to judge if a woman is a real woman or not?").
I feel like a lot of the posts in this thread are missing what he's actually trying to say here.