Have you considered it might be their life's outlook? What do most of these girls have to look forward to after school? A well paying job? Most of them will have crap jobs barely scraping by, and most of them know it. A house? Most will pay absurd rates for an apartment and never build equity.
Our school system is pretty trash too, depending on state. I think social media might be a scapegoat, because it's easy to, "just do something," while the real issue goes against the political donor's wishes.
Don't get me wrong, I'm a capitalist, but business have done everything to push down wages and working conditions since Reagan. Would you want to be a kid today with our current outlook?
And then there's the news. Kids don't realize it's mostly fear mongering BS and they believe all the doomsayers' predictions. That's pretty hard for a 14 year old.
Social media probably has something to do with it, but we have to fix all the other stuff too if we want to actually make a difference, rather than just feeling like we made a difference.