One of the fundamental ideas underlying modern seduction is this: our instincts are out of place in the modern world.

Our brains are designed to live in a stone-age tribe of about 150 people, give or take. In that situation, each female's job is to secure commitment from the highest-value male she can. Her tool for securing that commitment is sex.

In a small tribe, everyone knows everyone else, and they also know each person's status. The tribal chief is highest status. There's the second-highest status guy, his son. And then there's the 3rd, 4th, and 5th, etc.

If the chief's son picks a female to mate with, she will instantly go fuck him, no game required. Why? Because this is her best chance to garner resources for herself and her offspring. In fucking him, she hopes that the oxytocin and assorted bonding chemicals will take their effect on him, and cause him to desire commitment with her. In a small tribe, this was likely to result in a pair-bond, due to the simple fact that there weren't a lot of options, edit: and the fact that she's probably now pregnant.

In the modern world, we live in cities with potentially millions of strangers. There is no "chief." So, there is NO LONGER SUCH A THING as "absolute status." "Status" is now entirely based on social skills, aka Game.

When a woman goes into the modern-day nightclub, there could be five or ten guys who have the requisite game to attract her. Her instinct, again, is to fuck the highest-status guy ASAP, because that might be her only chance to exert that sweet cocktail of bonding chemicals.

Unfortunately for sluts, they are no longer in short supply. In a tribe of 150, you can't pump-and-dump a woman; there might only be twenty-five females of eligible age. In a modern city, a Player with Game can run through hundreds of women without any negative repercussions.

Sluts get screwed over because they are indulging in obsolete instincts. It's just like our desire for sugar: back in the day, it was only found in fruit, which is generally a healthy thing for humans to eat.

Nowadays, we have refined sugar everywhere, causing legions of people get obese and develop diabetes.

Sluts are like the obese diabetics of the sexual world: they are over-indulging in instincts that were once beneficial, but now are harmful.

Mankind's solution to this problem, for thousands of years, was religion-enforced monogamy. However, within the past two generations, liberalism has destroyed religion as a cultural phenomenon, effective cutting the brake lines of female hypergamy.

It's a good time to be a high-status male.

Edit: /u/MattyAnon pointed out something excellent:

A peculiarity of modern life is that women are spending 10 years having sex without getting pregnant. This would not happen naturally, and genetically speaking this is a problem that is solved by increasing desire and therefore having MOAR SEX. A great time to be a high-status male indeed :)