It's less a map of the territory, and more a set of directions for getting from point A to B, with hints at the geography. Depending on the specific flavor, it's more accurate than some, less accurate than others.

For an average heterosexual man, the overall thrust of the advice (be confidently dominant) is more-or-less correct with regard to the average heterosexual woman, and significantly more correct than the standard modern advice men receive (be humble and nice). The actual details advocated in PUA vary by flavor, but cluster loosely around "correct" (unfortunately often falling into the uncanny valley of human relations, as nothing is more off-putting than something that is almost, but not quite, right).

And implementations... well, the general gist is right, and the details are close to right, but hand that to somebody who doesn't understand why they're doing what they're doing, and you get something terrifying, because now you're several degrees off of "close enough" and firmly into the territory of "this person isn't behaving like a person", which is more or less exactly what the word "creepy" conveys.