A False choice
The real choice is either believe in the fairy tale conspiracy promoted in the article you posted or to believe in reality: Al Qaeda Agents, having snuck in to the USA over the previous years, organized them selves under means of direction not yet fully divulged, and executed a conspiracy to highjack multiple planes in the USA and use them as terror weapons. Of the four highjacked 11 Sep. by Al Qaeda agents, three found targets. It is possible more planes were scheduled for highjacking, but that is unclear.
And since it is known beyond any reasonable doubt that their were Al Qaeda highjackers highjacking the other planes on 11 Sep., there is not any reason to doubt that there were AlQaeda agents on the fourth, Flt. 77.
Ed