Earlier quoted context omitted.
Don't forget this link, the anonymous GitHub employee response to Horvath's claims: "Facts Conveniently Withheld". https://medium.com/p/d96f431f4e8e
And here's Theresa Preston-Werners side of the story: What every founder fears - https://medium.com/p/2fe173c44215
FULL explanation: It comes down to the unrestricted access that was granted. It introduces a person with extreme power but carries no responsibility with regards to work or culture. The end result is what we have today. This type of culture is actually very prevalent in asian companies (where families have unrestricted access) and have been demonstrated to be extremely detrimental. Theresa Preston-Werner blog post is extremely telling where she says "I have many close friends at GitHub, and I certainly had reached out to them when I began to build my company". My wife made the same mistake at her first job (trying too hard to be friends), except that she was an individual contributor and not the wife of the CEO. Her co-workers could just tell her off and she quickly learned the balances that were necessary. It's obvious that Theresa had no experience of this kind and had too much power for people to say "no".
I want to add, I think there was an overfocus on gender issues by all parties (victims, plantiffs, media & company) in the first place. When I read the original article, I felt that regardless of the incident, Julie Ann Horvath was just pulling out the gender card. This was a mistake since it gave Github an easy way out to simply deny the gender-based accusations without any wrong doing.