This is indeed embarrassing for parts of the US government, but look... they were rejected by civilian government (and this was decades ago, imagine the impossibility to do so in recent times) so this doesn't qualify as ammunition for conspiracy theories.
I have said it time and time again, 9/11 is not what government conspiracy looks like. The Clinton affair or Watergate scandal is what government conspiracy looks like... it's small, localized, and benefits a very small group of people in very, very obvious ways. Even with the small amount of exposure it is still often exposed and punished. What almost every conspiracy theorist has in common is that they perceive the government as a single ominous entity orchestrated by some kind of hive-mind. In fact, though, only monarchies and dictatorships have such a design that they could operate successfully in any way close to that. That's not how the US government works and if you don't believe me, you better go arm yourself against your mailman because he's a part of the government too. Maybe he's planting mail to lead you into a state of compliance... no motive for that? Who needs reasons, it's the government.
Where's the motive? Some people have said that it was to inspire war... and they would probably quote this as evidence. In fact, it's evidence that that was not the reason, since the US has demonstrated that if such a thing were conceivably true it would require approvals, would not necessarily be inspired by money (oil), and would not have been nearly as large scale as 9/11. There are ways they could incite a war on false grounds without crippling our own economy and killing over 3,000 people. That doesn't make sense, especially in the wake of this 'evidence'.