But in a lot of cases - especially the case of 9/11 - after years of debating people and presenting the same clear, obvious, 'in-your-face' irrefutable evidence ...
And people who have heard that same evidence over and over, are still in a state of denial and still actively fighting against the evidence without a rational leg to stand on?
People lose their patience.
This has been going on for years, man.
Some people don't have it in them to evaluate evidence based on reason.
ie. they are scientifically illiterate. Or they are primarily emotional people who are deep down afraid, or attached to authority like a child is to a parent. Or they are hardcore conditioned statists who deify authority and defend it irrationally to the death.
Even if they are regular readers and posters on the DP -- this is no guarantee that any particular individual has it in them to think critically.
Their brains are not really wired for reason.