1. That first statement isn't true, and you will never come close to proving it is. It's a broad generalization.
2. The comment you're responding to says, "Anyone who is a pickup artist is an asshole", which is synonymous with "All PUAs are assholes", so you haven't contradicted his point.
An interesting thought experiment would be to consider what you'd think of a female pick up artist.
Probably the same way, but being a female pickup artist doesn't carry all of that "constantly objectified in media" and "the subject of a steady stream of slut-shaming (but if she doesn't put out she's totally a bitch)" baggage that's there when a man is trying to manipulate a woman into having sex with him.