Hi everyone.
I am in my last year at uni waiting to start pilot training but I have been working on Security at a major airport for the last 4 years. I must agree a lot of the security seems like utter nonsense from a flight crew’s point of view. I can see where what you mean and agree, a lot of it is utter nonsense. However, you have to look at the bigger picture. Most security agents (there are the odd one or two) are not out to get Mr Pilot to make themselves feel big and powerful, they are merely doing their jobs and tend to have up most respect for pilots so if you do not agree with the system, please do not argue with security, he probably feels the same way as you do.
A few things I have leant along the way, security is not about making sure every passenger and every bag is 100% guaranteed to be secure, that would be impractical. It is about creating a deterrent. Ok there are holes in the system, but as long as they only appear randomly then the security remains intact as Mr terrorist doesn't know where the holes are. Also, security has to be seen to be checking everyone as they never know who’s testing the system, even someone appearing to be a pilot could be a test of security in disguise.