It is a wacko conspiracy theory because crashing a 767 loaded with JP-1 is more than adequate to explain the collapse of the building. If you require something more complicated that either (a) you are abysimally ignorant of statics and dynamics (which unfortunately describes the many Americans that avoided mathematics and physics in school) or (b) if you understand basic statics and dynamics, and are aware that a 767 loaded with jet fuel was a sufficient cause for the buildings to collapse, then you are a tin-foil-helmet candidate.
So which is it?