The first articles mention how Caleb, first introduced in the episode "Dirty Girls" is a caricature of the Church by not only looks, but what he says : "If there is a disaster in your area, don't turn to God. You just rejected him from your city." He seems intolerant at first, but not misogynistic. That is, until he sticks a knife into a young girl's belly as a warning to Buffy. Through Caleb, the article mentions, we get to see a different oppressive system at work- the Watchers Council. Whedon used Caleb's overt intolerance to show the Councils intolerance. One may have noticed that there are always new Slayers, but the Council always stays the same. It's no surprise that they have to send Watchers for the female slayers, lest they break free from the Council's control. Buffy's, being as smart as she is, picks up on this fact and tries to break away : "See I've had a lot of people talking at me, last few days. People just lining up to tell me how unimportant I am. And I finally figured out why. Power. I have it. They don't. This bothers them."
So, the way that the show reflects reality is quite surprising on some levels. Both Buffy and the nuns are both fighting patriarchies which control them in different, but rebellious ways. The nuns are doing it by trying to reinterpret their faith, while Buffy does it by asserting her independence. It's important to keep that the universe that Buffy lives in isn't real. Rejecting a patriarchy is not easy to do in reality because there are few women who have as much power as Buffy. And even if women were able to get rid of patriarchies and set up matriarchies, there would be any difference. Power corrupts, and absolute power corrupts absolutely.