tsadude, here is the fallacy of your whole argument (among others, but this is the biggie.) How do you know that if airport security had been better, there would have been no 9/11 tragedy? Perhaps there would have been one anyway. Or something worse. Or something else entirely but also bad.
The lunacy here is that there is something special and unique about airplanes and airports. If a terrorist is a terrorist then he can do his thing anywhere there is a crowd.