The reason indifference is attractive is because indifference is a sign of strong focus, of a man who cannot be easily distracted, and most importantly, from the point of view of women, because it means that a man has goals beyond women.
To be kind to women, or to pay too much attention to them, means that your focus is weak, either because you have no focus at all, or because your focus are women. Women can recognize this because they themselves are creatures of a weak focus, and women can despise this because they themselves feel helpless and in need of a man who is superior to them.
Indifference is quite simply a consequence and not a goal. Once you make it into a goal, it is no longer genuine indifference, but a trick a man with a weak focus, a needy man, uses in order to attract women.
Kindness and meanness can be rational, but for the most part, they are lingering habits that a man of order has to trim so that he can aesthetically synchronize them with the rest of his being.
Women are attracted to any kind of focus, but biological focus, which is aesthetical focus, is superior to mechanical focus, which is rational focus.
In fact, from a biological point of view, mechanical focus isn’t really a focus since in order to maintain itself it has to be sheltered from all inhibiting drives. Once you look at the full biological picture, you will see that the drives, taken as a whole, are diverging and only selectively converging.
In hedonism, on the other hand, there is even less convergence, and mostly it’s pure divergence of drives. In real life, this manifests as a series of short-lasting activities all of which are more or less unrelated to each other. Hedonism is easy and pleasurable but ultimately empty.
A sense of continuity is necessary, of movement from one point to another, where very little is lost of who I really am.