Because its not "game." In the way we men interpret game (see, open, escalate, seduce, sex) women don't do that and I honestly doubt they are capable of it.
Think about it...
We open a girl, we use touch, stories, games, small talk, teasing to create comfort and build sexual tension. Then our logistics have to be on point, we usually have some type of currency exchange (drinks, food, taxi, etc), and then we have to continue gaming her at her place to actually fuck her. We operate from a place of persuading a girl that we are a high quality male that she should fuck.
Women do not operate to persuade us that "I am a high quality female you should fuck" state of mind. Women don't approach, lead the interaction to make us more attracted to them, offer an exchange of currency, and then game us into fucking them. They know we want to fuck them. They never push an interaction to sex--they can only make themselves available for
us to push the interaction to sex.
How many times have you had a girl push through your own LMR? In all instances of you banging a girl Im sure at some point you realized she wanted to fuck you and then
you made a decision to go in for the kill.
A girl walking up to you and saying "hey lets fuck" is not solid game at all. Is someone that knows men want to fuck her and just putting it out there--no skill involved...
I define game as the skills used to satisfy the biological imperative: survival of the organism; survival of the species--this one pertains to the conversation at hand.
A man needs to spread his seed and have as many offspring as possible.
A woman needs to find a strong male to reproduce with and have stay around long enough (9 months) to protect her.
Our "game" is different from a womans "game".
Hers is to extract resources from us and ours is to impregnate them(or at least pretend to). A woman running game on us is attempting to persuade us into committing to them. A mans game is persuading them into fuck.
Can a woman have tight game. Yes
But not in the way/methods that we think about game. A woman cannot have man game because...why would they?
edit: Lesbians can have man game in theory but even that is WAYYYYYY different so I just call it lesbian game.