Many romance based relationships(as opposed to money based/gold digger types) start out sincerely with both parties affirming the positives they identify and admire in the other.

As time proceeds, and as the strong female turns out to be "right" more and more, the male begins to feel less and less powerful vis a vis the female. Each relationship being unique, one cannot generalize regarding certain specifics, however, the hardwiring of the male is such that the male ego in order to continue feeling ADEQUATE, demands that he feel needed, important, of use, and slowly begins to wither with the increasing realization that his female displays continual superiority in so many ways.

This is addressing only those relationships where there is a very powerful, strong female, not at all looking at the lower IQ, or submissive, even masochistic type females.