I'd blame falling birthrates on the fact that everyone is poor and too busy working jobs to actually have a life. Dating is awful right now, and people can't even afford living in a house. On top of that global warming threatens to plunge the world into chaos in the next 50 years and our government is falling into fascism at an alarming rate.
" There is no problem that can't be fixed and no problem that won't be fixed without youth on board"
There are absolutely problems that can't be fixed; Even with youth on board. When those problems have already started before you were born and their ramifications will be felt for centuries, and you see earlier generations who caused it doing next to nothing to stop it, a lot of people lose hope for the future.