The trouble is that airport security always has been a knee-jerk reaction to the last incident, in an attempt to reassure the travelling public that it can't happen again.
The terrorists meantime are planning the next attack on the weakest link. Firstly we had hi-jacking, the response was to introduce screening for weapons on the person. Then we had suicide bombers/9-11 terrorists who were prepared to die in the attempt. So now we have yoghurts and metal spoons banned. Then we had the Glasgow incident and now cars are being kept away from the front entrance to the building. The next incident will doubtless be something new, several of which I can imagine but won't mention here for obvious reasons.
We have to be more forward thinking and looking for the next weak link instead of having all these dim jobsworths going through the motions in the pretence that it is making us safer, when it patently isn't.