I've already mentioned this on the rotorheads forum, but given that none of this nonsense is actually going to stop anyone filing a bogus FP, loading their aircraft to the gunnels with high explosive and then launching same at one of several Government/State buildings (before anyone has the chance to say 'scramble'), what precisely is this restriction supposed to achieve?!
The whole thing is ridiculous and it certainly wouldn't stop an attempt, but I guess the main reason is in the event of a successful attack the agencies involved will all be able to say "well, we did all that we could".
Similar reasoning accounts for the absurd limitations on liquids and checks on shoes at airports.