First off, I do not believe we are all just wind-up automatons executing a program hard-wired into us at the DNA level. We learn from childhood forward. We have brains capable of thinking about what we have learned, and modifying behavior that might otherwise have been innate, based on learning and thought. But even if that were not so, even if our DNA told us whom to fancy to maximize said DNA’s chances of survival; we do not all have the same DNA. So we still would not all chose the same sort of mate.
If all human males were focused on surviving through finding and mating with the perfect paragon of woman, and all of them agreed on what constituted said paragon of womanhood; that would virtually assure the destruction of the species within a single generation, not it’s survival. Even the simplest of lifeforms don’t all fancy the same sort of mate, and for obvious survival-driven reasons.