I don't think I'd go so far as to label anyone "sexist"

I would suggest looking at the threads that have been made about how "disruptive" or "unfunny" Erin is at varying points in the Harmontown timeline. While there are moments where Erin isn't funny (the first game corner springs to mind) there are 1000x more examples of Dan or Jeff being unfunny--like the entire HARMONOLOGY episode or a heathly chunk of Hug Me, Hug Me, Hug Me, or even old episodes like A Four Day March to the Butts Expanse--with the only difference being that this sub often seems to give Dan and Jeff the benefit of the doubt in these situations instead of ripping into them like they do Erin.

I've seen a disturbing trend the last few months of this kind of vile fan behavior popping up more and more as the show gains "popularity"--go look at all the nice things people had to say about Lana's Shadowrun session in Dick Pic. What worries me most is that this vitriol clearly comes from a place of expectation, that these fans have been fans since podcast #X and thus feel entitled to what they believe the "true" Harmontown to be, and, unfortunately, you can tell by the way that some of these people gush over Dan, Jeff, Spencer, Kumail, Mitch, even Rob Schrab the Taintmaster, without mention of Erin save for "She's pretty," or "I hate Game Corner", or worse, that what they're expressing is just a more articulate version of "I don't want girls in the clubhouse."

While I will concede that some of this response cannot be helped--the Harmontown audience, I imagine, as a whole, does a poor job of filtering their thoughts on the way out the mouth--most of what I've seen boils down to men complaining about a woman for taking away their man-on-man time with Dan and Jeff and Spencer and the whole gang. Aside from this attitude being hurtful to other fans, such as myself, who still see Harmontown as one of life's true safe spaces, it's insanely unfair to Erin because it isn't our job to mitigate and "correct" her behavior, even though discussions about doing so come up from time to time, with the same people always assuming that Dan or Jeff will self correct.

I love Harmontown, I really do. I wouldn't give this show back for all the bearer bonds in Nakatomi Tower, Erin especially, but I could do without the fans that think they have any right to tell the cast that they're doing the show wrong; and this always comes up more than when Erin is given a large swath of time to talk.

tl;dr: The Harmontown fanbase has some whiny-ass men that don't like women getting screen time in "their" podcast. Search the sub for threads with Erin in the title if you don't believe me.