Pretty simple...
A relationship is about compromise. And if you think you are better than everyone else and not willing to compromise, then you wont find a mate. Or if you do, your relationship is destined to fail.
Probably why a lot of the Hollywood crowd don't stay married very long.
Actually, the reason why "single smart women despair of ever finding true love" is because the only "single smart women" that matter to these writers happen to be "single smart women" who coincidentally happen to a) have trouble with relationships, and b) are writers of articles about their own woes.
Basically, their position is that if it happens to them, it must be happening to everybody.