I've written about this before on some of the community forums and figured I'd toss up this nugget of wisdom here as well.
To put it bluntly, women that approach men are more often that not LSE, UGs, and/or Cougars. The truly high value females don't approach men all that often. They don't need to. They have pick of the litter, know it, and just screen for the best of the bunch. High quality women get approached all the damn time, upwards of 10-15 times a day if they go out dressed to the 9s.
Women tell me it's a pretty simple process: They know they're hot, guys want them, and just filter out the losers from there. Furthermore, they know that if a guy doesn't approach them that it usually means he's not in the high quality crowd (read: AFC). It's a pretty economical process for them, so why upset the balance by going after guys? Yes, some women certainly do approach guys on a rare occasion (like if they're drunk), but that's not a normal behavior you'll see from high value women (approaching, not being drunk).
All in all women chasing guys is pretty damn rare in our society. What it all boils down to is that high quality women know they're the prize and behave as such. High quality women don't chase. This is why flipping the script is such a powerful thing and works so well on them.
And a note about cougars. I don't want to conflate cougars with the notties. Some older women are smoking hot HBs in their own right and are just confident and comfortable with themselves and buck the social norms by actively pursuing sex. I'm all for that. However, it doesn't change the fact that most of the women who actively pursue men are of the lesser value in the sense of what men rate women for--namely the ability to produce healthy and attractive offspring as indicated by youth, facial symmetry, hip to waist ratio, etc.