>[...] they'd rather believe in some evil cabal that makes bad things happen.
The flip-side of this is also true. Many people reflexively reject alternative theories because it makes them uncomfortable to feel like they're being manipulated by powerful actors. I'm not saying that's the case with 9/11, although, I suspect we were never told the total truth about that day (as with most big news stories.)
The frustrating thing is that there are people who will simultaneously be skeptical that oil and coal companies have worked to downplay the risks of global warming and slow the adoption of green energy, while believing that a car engine that runs on pure water was invented in the 70s but suppressed.
The flip-side of this is also true. Many people reflexively reject alternative theories because it makes them uncomfortable to feel like they're being manipulated by powerful actors. I'm not saying that's the case with 9/11, although, I suspect we were never told the total truth about that day (as with most big news stories.)