It just means that men are very considerate about who should be their lifelong partner on the basis that women are more likely to get aggressive towards marriage as they get older because the biological clock favors men more than women.
For example, an older man is more likely to have healthy babies than an older woman. You know what I mean, don't you? Another way to look into this is that most men are commitment-phobes. So when comparing the ratio of women and men on the market obviously there are too many women wanting high-value men.
But are those high-value men ready to change their lifestyle of casual sex with numerous hot women and finally settle down anytime soon? Well, probably not -- only when they want to!