Couple the Govt doing something most everyday people would consider unthinkable, lay down a huge smokescreen of "seeming plausibility" via MSM, and the truth is accordingly going to have a tough time rearing its head and being seen through the smoke.
Fortunately, the 9/11 attacks were carried out so poorly, that there are a ton of cracks that the truth has opportunity to reveal itself from.
My hope is that in the near future these chinks in the official armour become so apparent they will force themselves to be dealt with.
It simply a matter of time till this happens, how much time is the million dollar question.