Why can't girls be direct?

this sounds plausible i suppose

Why do they have to be indirect (or at least the ones who I like)?

Women aren't direct because they usually play a long game.

Women are only after an improvement in their circumstances - be that socially, emotionally or financially. They want more fun, companionship and/or material goods.

Men only want more sex.

The only reason you want a girlfriend is to have lots of sex, and preferably with the person you like most.

She might or might not want a boyfriend for that increase in utility.

She is quite possibly concerned that the only value she has is in her novelty. Once you've done her, she's no longer interesting and you'll move on to someone else, and she's invested time in a "realtionship" that has led nowhere and gleaned her very little. On a larger scale, this is also to do with the enormous disparity in the length of men and womens reproductive cycles. Yours lasts between 1-20 minutes. Hers lasts 9 months. Biologically, she can't afford to pick a loser.

In this, there is an "immunisation" effect amongst women, like with measles vaccinations. If enough of the population are immunised, measles disappears, or is suppressed. If women all club together and play hard to get (or basically don't put out within 5 minutes), a man knows that if he kicks one girl to the kerb after having sex with her, it could be a long time before he has sex again, as he has to start over with someone else.

This is why girls hate sluts. They're the equivalent of the people not getting the MMR. They're de-valuing the commodity that other women have.

Because being direct takes balls. And only men have balls.

It's the man's job to be direct

Say whatever you want, but ever since you shaved your mustache off, I don't respect you anymore.