Basically this is a problem where the female vagina no longer self-lubes properly, requiring artificial lubrucation to allow sex to occur. The author of the RoK article calls it Sahara Snatch and states that it indicates infertility, generally due to hormonal fucked-up-ness. I just call it Sand Bucket (as opposed to Cum Bucket) and went looking for another better-lubed hole.
The problem is quite widespread amongst the 30-something crowd, probably getting worse for the 40-something crowd. Above 50? Who the fuck knows? (Or wants to know.) In contrast, I've only run into it with a single sub-30 woman.
As for the cause, who the fuck knows? My opinion is that if you're shoving a cactus up your cunt and masturbating at 240 RPM to 50 Shades of Grey then the chances are you're gonna fuck something up pretty damn good. (Image stolen without fucking shame from Return of Kings.)
Apparently your hormones and fertility are the first to go. When your hormones go, your looks quickly start to follow. As the RoK author states, it's probably not helped in the slightest by the use of The Pill: artificial hormones that take the place of your own.
"No, wait! The Pill has been scientifically proven to be safe!" Wrong. Like they didn't test thalidomide on pregnant women, they didn't test The Pill on women over a 30-year multi-generational timeframe to see what the long-term effects were on her fertility. It ain't looking good.
At any rate, the incidence of fertility drops drastically as age goes up - doesn't help that by the time you're 30 you have only 10% of your eggs left. After a 15-year burn, the last 10% are supposed to get a woman through the next 10-15-years to 40 or 45? Yeah, right. By the age of 30 you are sexual and reproductive toast.
But wait - there's more! Even if you are infertile you can still have a baby, courtesy of IVF (in-vitro fertilization - aka have a test-tube baby). At a sweet US$12.4+k a shot, here are your chances of success:
Under 35yo - 39.6% success
From 35yo to 40yo - 22.4% success
Over 40yo - 11.5% success
Notice that they actually have statistics on under-35yo women. It's pretty fucking sad when they have these statistics for the years of a woman's so-called "sexual prime". Those little numbers there alone blow every single argument about a woman's sexual peak being in the thirties and fourties to shrieking shreds of feminist denials.
Good luck hunting for numbers as a percentage of actual fertility on the web - not easy to find. You might have to go to a clinic because they basically don't tell you elsewhere. All they say is: "If you're not pregnant after a year of trying, you're infertile." Too scared to let that info out to the general public?
Remember: "infertile" is the politically-correct way of saying "sterile".
One little stat that I could find is that at least 12% of women under 29yo are infertile (sterile). Which might be the reasoning behind the sudden resurgent thought of "25 is the new 35" - at least for women who want to have problem-free kiddies of their own. Yeah, I haven't mentioned much about sweet problems like Downs Syndrome and the like, 99+% of which is caused by eggs from older mommies.
Welcome to your daily dose of poison, you poor deluded mommy wannabes. Your choice: 14 years of sex-fun-play, or a family. I can smell the fucking toast from here.