The late 90s were full of media that questioned reality and authority - like X-Files, The Matrix, Dark City, all sorts of websites about conspiracy theories and UFOs, etc. The zeitgeist was full of speculation about hidden truths. The cultural mood was defiant and sardonic. There was rap, rap-rock, Beavis and Butthead, Fight Club, Office Space... One of the most popular pro wrestlers in the world played a character who beat up his boss and gave him the middle finger. Then after 9/11 it kinda seemed like suddenly the TV shows were all about cops and soldiers. Admittedly, my memories might be somewhat deceiving me. But I do feel that the mood suddenly shifted, much more than the actual damage done to America by the attack should have justified.