1. It teaches that it’s cool to be yourself
Agree with this one! If there's one thing that is true about BtVS it's that characterization is constant and character's are truly themselves. Plus, the whole idea of the show is kind of about defying stereotypes, so that's cool.
2. It has strong female characters
Again, super agree with this one. The characters in Buffy are extremely flawed, but they are often also very good role models. They aren't just goody two shoes of Mary Sues, they feel real, which is even better. I don't want to see an heroine that is perfect just because she's a woman. That is boring and put unrealistic expectations of what a strong female character should be. Buffy doesn't do that, the characters manage to do awful stupid things and still put up a good image of strong characters.
3. It portrays a positive sexual image of women
Concerning Willow and Tara (which I think is mainly what they are saying), I couldn't agree more. These two are the reason I understood that it was okay to be gay. I went to catholic school in a fairly small town where there was zero diversity. It was normal for people to make homophobic comments and gay was used extensively as something negative. That sucked, but Buffy was the reason I stuck through it and realized that things were going to be okay. People, especially at the time, needed a show that portrayed a realistic gay relationship.
As for other characters, obviously everything was not always a positive sexual image. If were talking about Spuffy s6, then obviously it's very negative. But I think it's equally important to talk about abuse or other issues in relationships. Buffy opens up the door for discussion on serious issues which is equally important.
4. It doesn't shy away from serious issues
This one depends on the context. Again what's great is that the show open doors for discussions related to hard issues. The issues weren't always dealt with properly on the show, but at least it touched on those issues.
5. It teaches you that recognizing someone else’s strength doesn't diminish your own
I really like this one, not something I would have thought about if I made that list, but I like it.
13. This show started the whole vampire craze! It might be copied, but it will never be surpassed 😛