The evidence of this is the hours of audiotapes he recorded which was covered in several NYTimes articles.
The odd thing is the plot started before Ramzi Yousef entered the country. And the two Iraqi brothers, where Yousef first went, and the lady associated with them, were never caught.
I don't think it was a malicious conspiracy but it was gross negligence and there is indication that the FBI wanted to catch the terrorists in the act to teach them a lesson. Even worse is that KSM is Yousef's uncle and there were several neo-con writers who cast doubt on Yousef's true identity whilst trying to link him to Iraq.
The Saudi's have a history with this sort of behavior.
Their islamically led ideas of expansion have been around since the 18th century and oil is their vehicle of perpetuating that meme.
The American people have strong values and big hearts. You shouldn't confuse their apathy for politics as a lack of sympathy.
The second fly in your ointment is that you assume the source to be credible. If it is credible, then at some point other news companies will be forced to recognize that credibility.
But, sadly, the NY Post has a history of exaggerating the truth and bending it in ways that will inflame and influence people like yourself, making you the one who's being told by the media what to think.
There's nothing particularly controversial in this. Most of these facts have been long reported - just in isolated dribs and drabs over the course of the last decade and mostly people are disinterested in hearing it.
They care. You can't do anything about it though.