If everyone conformed to reality, most people wouldn't get a University degree because of the prohibitive costs and effort involved. "It's too hard to study for 5 years and spend thousands of dollars. I'll just settle for a Mcjob instead"

I've seen the tragic results of relationships on most people I know (jealousy, possessiveness, loss of social life...)

His logic is that unattainable women are used to being complimented often by guys, and they have fun with that, leading guys around or turning them down. But as soon as a man comes up to them and not only doesn't fall into their trap, he stands up to them and disses them, their "bitchy" confidence comes crashing down and they come to him like a magnet.
He's been doing it for 5 years, and says it works 8 times out of 10. And he's never been slapped or physically attacked once.
In a way, it's kinda sad that you have to resort to this approach to pick up women in clubs, but it's the reality.
That being said, I'll never have the balls to try this particular technique

On the other hand the approach your friend uses places him at a higher social value: he is now the one judging her, and it puts her in the position of having to justify herself to him.