Secondly, I am not sure that having fewer men would be a good idea in the long run, since (as others have mentioned) it would have biological implications.
Thirdly, I am not entirely convinced that if there were fewer men, some women might not similarly take on the roles previous men had played.
Finally, I would like to say that I understand your pain and frustration regarding *certain* men, but I think it is essential to not overgeneralize to all men. Otherwise you miss and inadvertently put off the good men when they do enter your life. And they do exist, as you so aptly stated.
Also, consider the following: All judgment is based on standards, so if you raise the bar, then what you now consider excellent will be the new normal, and the "nasty" will be some form of the current "average" and it might be very hard for a man to "wow" a woman. It's all relative, really.