I understand your concern, and feel pretty much the same way. However, based on what I've learned over the past six years with two teenage daughters (one turning 20 this mont and one 17) who've pretty much stayed on the straight path, it's not just the obviously selfish, self-centered and vain dolts who end up in these situations and making very bad choices. It can be girls they've known all their lives and have gone to Sunday school and through Confirmation with, girls and boys whose parents we know, and know they've been caring, involved Christian parents. In some of the cases we've shared (through our friendship with the parents) the agony of seeing kids take a bad turn and hurt themselves and others. So, to paint the pictures so starkly is likely to be inconsistent with the teenagers actual experience. The teaching points are strongest not when they are portrayed most starkly, but when they are most believable and consistent with what the kids actually see in their lives.
That's an excellent point to ponder. We homeschool and allow about 1 hour of television a month for our children. We strive to protect their minds until they reach an appropriate age where they can better understand the more adult issues.
But... what can you do about the children they get to know in little league and other sports? Also, our family does not share our passion to protect the minds of our children, and they let their own children have access to things we find completely unacceptable. How can you protect the minds of your children from cousins and others that may discuss inappropriate issues for their age range?
You can do your best, but there will be many times children will be exposed to something they shouldn't, and often times from family.
While I can't really endorse the book without reviewing it myself, unless we live in a cave, children will be exposed to issues many folks find objectionable, and other than doing our best to proect their minds, there's little to nothing we can do about some things.