Earlier quoted context omitted.
Limiting the gender is probably expressly intended to limit the talk in a particular way as one of its central motivations. (It may limit it in other ways as a side effect, which may either be something the organizers haven't considered or a price they are willing to pay.)
He's posting for his wife for a meetup he wants to have at his house where presumably he can stand guard. Not to be offensive but I think the main thing he's trying to limit is temptation from his precious wife.
That's unfair. It's as likely that she was uncomfortable and this was a way to mitigate her concerns. I was very uncomfortable going to my first meetups around tech and most of those concerns turned out to be valid, so I can't really hold it against them.