You just said "we," suggesting you didn't see anything we didn't.
So what exactly do you think you know that you think the rest of us don't know?
Actually, two were mustered (out of a total of 14 on active alert at the time). None of them reached the planes in question in time to react. This is partly because, as you just said, the planes' transponders were turned off and so civilian air traffic control was forced to locate them by hand among almost five thousand similar planes in very crowded airspace. And this is despite the fact that airplane intercepts were not routine even in the case of confirmed hijackings.
I don't know why you think an airplane would be easier to find with its transponder turned off. This is basically the only means air traffic control has of identifying where a plane is at any time short of the ludicrously inefficient hand-check system they were forced to resort to.
And even if none of this were true, at worst it would point to managerial incompetence, not deliberate orchestration on the part of the government.
How? Saying so does not make it so. (BTW, it's spelled "proves.")
Well, to be fair, it's the conspiracy theories forum. 
