Hi. As you've mentioned it is hard. But just stay strong. I'm a mother of a daughter. Now she's past teen years. But, I've experienced something similar. So, it was either to join them or fight it all the way. So, I decided to be strong as my parents have raised me "humble, good morals, respectfull to anyone and thruthful to myself".
I believe, since the jk and sk are larger numbers and long hours it might be that the poor children aren't guided properly on how to behave , tv shows also aren't the best role models. We need to guide children towards achieving acceptable social skills (everywhere). As a quote says "correct your child with love and kindness now or the out world will do without it, in the future".
I can see, you had a good solid based upbringing. And I'm very sure you expect same for your daughter. With my experience I can tell you that it took time and patience but after all my daughter learned to choose good friends on her own. It took patience to explain everytime I could, why wasn't allowed to invite or visit certain "friends". And now that she is almost finishing high school, she made really good friends, they are respectful and supportive. Hold on there, you will find someone who shares your parenting skills and a good friend for your daughter. Try to visit library groups, weekend playgroups or some other activities you will see that there are people that shares your thoughts.