Bordering on rude really isn't the way to do this stuff. It's still not the ideal frame to come from in terms of enjoying life and being successful with women. It is simply more effective, if not too extreme or seemingly backlash for a lack of success with women, than the worst possible frame of timid mommas boy. Timid mommas boys and woman haters are terrible frames to come from, especially since they are so transparent.
Well, let's just take a look at what could be going on:
Greg is to some degree showing the following

there is much better ways of doing this stuff, let me add, and I'm not endorsing what he did as a technique or anything):
He's not needy. Most guys are total wussies who either try to hide their feelings in a way that comes across as really insecure/boring, or come unglued at the seams and profess their love and devotion before she's even sure if she likes him adding a mountain of pressure for her to recipocate or smothering her with hoardes of effection (see footnotes).
He's socially proofed. He can afford to blow girls off, implying he has other options. Indicating that women find him worthwhile. It's like buying a name brand car versus a ****titueuze 500.
He's created competition. To the girl there must be something wrong with her. Why would he blow her off unless he had something better waiting for him? To her, it feels like he has moved forward and she is left behind. She wasn't good enough for him, and now she needs validation.
You can take the frame of "I'm OK, you're OK" you just can't look at the world and see "I'm NOT ok, you're OK"
Footnotes:
Note: Studies show men fall in love first and hardest, although to some degree the man falling in love can cause women to go into a similar state--also keeps this in mind. Everything is both black and white. This is just basic state stuff, if you are in a given state strong enough it becomes more likely that the other person will also step into it. I've done this on many occasions, when you do the right sequence of steps from a place of power, giving yourself fully can overwhelm her and suck her completely into a state of being swept off her feet.
What causes people to feel in love is feeling that their love is being returned somewhat, bot not yet fullly, with the belief that it will be fully returned at some point in the future.