I think increasingly young people are not pursuing relationships until later in life. Notwithstanding this article, when you look at various surveys and studies, people are eventually getting around to getting married and having sex (though not in any particular order). About 96% of people will get married at least once, but surprisingly (to me at least), around 10% marry for the first time after age 45.

Hard to say how much of this is due to men behaving badly or even indifferently or women behaving badly or indifferently. I do believe that cultural, societal and demographic changes in the population are having profound impacts on the process by which the "dating game" takes place. it is interesting to see people try to analyze all the reasons, but I tend to believe the reasons are secondary to drivers... our society does not need people producing children like it did at one time, so they are not.