Nothing to do with her being a woman and it sucks to even bring that up - it makes no difference. I'm speculating here, but I think the problem is largely that Pao is an ex-lawyer, wealthy investor that is married to a hedge fund manager. Reddit being a largely liberal/young/mass appeal/quirky internet subculture collective (at least at it's core) would see any ex-lawyer, wealthy investor married to a hedge fund manager as an outsider. She comes off as an "out of touch 1%'er" that is there to make the site more corporate and "safe" for advertisers, ruining its culture to make herself even richer. It doesn't help that she apparently doesn't even know how to use the site.
It's like being a software engineer and getting a new manager that previously worked at Goldman Sachs, wears expensive suits to the office, asks you for help using Microsoft Word, but then tells you to switch from IntelliJ to Borland JBuilder because he owns some shares in Borland. He doesn't get the culture, he's an outside and is making decisions to actively ruin your environment. That's how it feels.
It's like being a software engineer and getting a new manager that previously worked at Goldman Sachs, wears expensive suits to the office, asks you for help using Microsoft Word, but then tells you to switch from IntelliJ to Borland JBuilder because he owns some shares in Borland. He doesn't get the culture, he's an outside and is making decisions to actively ruin your environment. That's how it feels.