Same with calling all those TWA800 eyewitnesses a bunch of drunks.
Timing...In 95, the military was stronger and not spread as thin as it is now. The terror cells here were not as developed. Atta was in Germany beginning his "mastermind" group.
I'm not sure about this, but I vaguely remember that some of the people (our gov't) at OKC had worked on the 93WTC bombing-so there might have been an element of revenge there.