Fight Club caters well to our post-modern generation by preaching things it simultaneously mocks. This line embodies this modern commercial necessity well.
"Self-improvement is masturbation." Amazing. But how many of you said: "No, that's a ludicrously adolescent thing to say; everyone who's graduated their teenage years knows very well that self-destruction is masturbation, that Trent Reznor and the process of glorifying one's own personal suffering into a poignant tragedy, that's masturbation. Everyone knows that."
A statement is made about the condition of mankind. This statement reflects a hidden truth, but looks and sounds good, because it's shrouded thickly in fashionable kitsch.
The people who are being criticized applaud. The people who are criticizing them applaud. Everyone eats their popcorn, speaks highly of the film, and buys the DVD.
Our main characters are on the bus. They see a picture of a guy in his underwear advertising Calvin Klein or whatever. Protagonist remarks: "Is that what a real man looks like?" Brad Pitt answers no. Everyone answers no. But is there any way around the fact that the guy in his undies looks like Brad Pitt?
Only from the safe dignity of kitsch can one effectively criticize kitsch.