Do you understand that the books are not about "profanity, sex, violence, abuse, rape, and incest?" 

Theses are books that help people view the world in a different way. The Color Purple is an amazing book about a woman who is oppressed in the American South and yes, she is raped. But the book is about more than that - it's about sisterhood and poverty and her relationship with God. The book is an interesting example of a different type of writing - The story is written in letters and as the main character matures and learns the writing becomes better. 

The Catcher in the Rye is about holding on to adolescence and I honestly don't remember much about sex, violence, rape, or incest, but it's been a really long time since I've read it. 

The Kite Runner is an excellent book for the time we live in. It's themes are not tied to the culture and while there is a horrific rape, I think the importance of this book and it's themes of redemption and family overpower the graphic imagry.