Call me crazy, but I don't believe there is any "crisis".
People today are more informed and more in touch with the realities of life. Whereas in the last generation you "blindly" got married because your mommy said "she is beautiful and amazing", or "he is smart and responsible", today people actually assess their potential lifetime partner.
A girl does not want to end up with a guy who can't provide for his family and doesn't respect and care for her or the kids, and a guy does not want to end up with a girl that suffers from serious emotional issues because she was abused as a child.
Would you believe that people actually want a lifetime spouse that they can love? Would you believe that people actually want to be happy?
Naturally, it takes longer to find the right match when you actually want to be sure that you like the person you will be spending the rest of your life with.