This thread has so far ignored the very high incarceration rates and unemployment rates among some male populations in the states. Being in prison makes it kind of tough to woo a woman.
Also, the parents of the GenX'ers were very vocal about "living your dream" and don't let anything tie you down. Get the job you love, go travel, and love and family will find you later, when you're ready. Don't rush into anything. So lots of us have done just that. Marriage is only one facet of a woman's life; it no longer has to dictate who she is. Heck, a married woman can even keep her own last name these days!
Basically: lots of reasons.
