In addition to the other responses I think it's also a matter of our unconcious instinctual reproductive goals.
Women by nature are very selective of partners because they want the best partner for the child they will have and obviously can only have one pregnancy at a time. This will lead women to often be attracted to that dominant male archetype. How often have you seen a whole bunch of women fawning over one man when there are plenty of other men available?
For men, on the other hand, our primitive nature is to have as many partners and children as possible to ensure that our lineage continues. This leads to a quantity over quality goal where some guys will 'sleep with anything that moves'.
This is obviously just my opinion but I believe the result of these two conflicting reproductive goals is that women are more content to wait for that 'perfect guy' while men are just trying to find anyone that will have them (within reason obviously but you will see many guys who have given up trying to find a great partner 'settle'). So you end up with women saying 'there are no good guys out there' while waiting for an amazing guy and tons of guys who are good but just not quite good enough to match the ideal partner.
The women are content to wait (for a while at least) while the men are tearing their hair out, wondering what the hell is wrong with them.