It was not a direct attack on the witlesses, even though many witlesses missed things on account of it. And justifiably so, since that was a major event that could have led to martial law that day.
In fact, there are 2 major theories about what really went on. One is the one that the media published--Muslims hijacked some planes and flew them into the World Trade Center and Pentagon. According to that, the Taliban wanted to bring America down because America was not Muslim.
The other was that the government itself planned this attack as a pretext to restrict Americans' freedom. It was planned, and the Muslims were in fact innocent though they got the blame. The Patriot Act was passed soon after, having been drafted sometime before the attacks, and this led to the attacks on our freedom we see today by design.
Regardless of which of these theories you choose to embrace, there is no way the witlesses were singled out. So some witlesses lost their special events, and others lost boasting sessions. But innocent "Satanic" businesses were exterminated, 4 planes' worth of people (worldly people) died, and travel was disrupted for the day. Worldly programs were disrupted. And I am sure many a party (including birthday parties) scheduled for September 11 or 12 were ruined by the attacks. And freedom to travel without getting cancer scanned or groped is gone to this day--for worldly people, not just for the witlesses.