An example of cognitive dissonance: Form your opinion by telling that "the collapse of the towers should have been brought by fire and structure failure.
Everybody who thinks it could be controlled demolition is crazy. Because our government would never do that and NIST tells also there is no evidence we can see."
If that had anything to do with how we formed that conclusion, then you'd have a point. As it is, we don't start from the presumption that everybody who thinks it was CD is crazy; rather, we assess the argument that has been put forward for collapse due to fire and structural damage, and find it to be compelling and consistent, and we assess the argument that has been put forward for collapse due to CD and find it to be riddled with internal contradictions, to contradict a large part of the available evidence, and to have wide-ranging implications which imply self-contradictory attributes on the part of the supposed conspirators. Nor do we start from the assumption that our, or somebody else's, government would never do such a thing; again, it is a conclusion, not an axiom, that the US government did not play a part in the collapses.
Cognitive dissonance is rather better displayed in a person who tries to reconcile a belief that 9/11 was an inside job with the incompatible knowledge that the majority of people do not agree with him, and is only able to do so by adopting the belief that the majority of people are easily led, unintelligent and incapable of critical thought. This forum presents a major difficulty to that particular form of cognitive dissonance, because it's frequented by people who are practised in critical thought, and indeed apply it very effectively to a wide range of subjects, including the wrongdoings of the US government. A common recourse is then to adopt the belief that the members of this forum are co-conspirators. Both of these are classic examples of an a belief being adopted without supporting evidence purely to reconcile two otherwise incompatible belief systems, which is more or less the definition of cognitive dissonance.
It is certainly not cognitive dissonance to say "This theory implies many other things which contradict the evidence, therefore it is a poor theory." It is, rather, another classic example of cognitive dissonance to say "This theory may or may not imply many other things that contradict the evidence, so I will refuse to make any attempt to understand the wider implications of the theory."
Dave