I forget who it was, but a while back someone here posted a plausible explanation as to why so many dudes get sucked into the PUA garbage. Something about how re-framing sexual relationships as a "game" with "rules" and "strategies" makes it more digestible for the kind of shy, awkward nerds who really just want a girlfriend but have no idea how to get one.
That's a pretty charitable way to look at it.
I've never heard the term "negging." That's nasty shit.
...What these guys do is disgusting.
I put it charitably because a lot of these dudes really don't think they're hurting anybody, and are greatly offended when accused of reinforcing rape culture and misogyny. That doesn't change the reality that PUA "techniques" and mentality are completely deplorable and disgusting, but a lot of these dudes are mostly just suckers (the creeps who write those books gotta make their money off of somebody, after all).
They'd meet a nice girl the proper, human way if they weren't hoodwinked into believing that it's a battle between cockshy vaginas and "Nice Guys."
It's sort of like... trying to tell someone who thinks that they've found a convenient shortcut that they are actually walking on puppies. Some dickface told them that the sign telling people not to take this shortcut is actually just a ploy to keep them from their destination, and they never bothered to look down at their feet. If you scream at them, they'll just get mad and keep stepping on puppies until they get what they want. You have to actually convince them to look at their feet and see what a bloody mess they're making.
Also, I've been drinking. Take this analogy with exactly 100 grains of salt.