Boys, boys!
Certainly the airport security process catches and removes many true weapons daily and it always has. It may be catching more now because it is stricter - That much may be a good thing. There are other items that are not safe on an airplane simply due to the airpressure changes that occur. Cans of aresol can break and make a pretty mess of your luggage etc.
Certainly with any security process you will have specified, standards and guidelines combined with the personal judgement of the individual on the spot. Officers occasionally shoot the wrong persons, such as a kid pointing at them with a water pistol at the wrong time and place. Airport security "rent-a-cops" become overzealous occasionally and the current guidelines may be too strict. Flying remains the safest way to get from point A to point B even with terrorism (which isn't new BTW).
If someone gets in my car for a ride accross town I won't put it in gear without everyone putting on their seatbelt. My choice, My vehicle - You can put on the seatbelt or walk. The airliners don't want armed individuals on their planes and never have. Leave your weapons or walk your choice. The government doesn't want airliners turned into WMD either so they will help the airlines disarm their passengers.
Many things are good in small doses that are not good in the extreme. Policy and medicine share this. It is good to have armed officers with the authorization to shoot bad-guys. It is good to be able to change the definition of who the bad-guys are as society changes. It is not right to take that to the extreme of having the Jack-Booted SS arrive at your door at 5:00 am and drag you off because someone declared you to be a bad-guy without informing you.
RANT ON<img src="images/graemlins/mad.gif" alt="" /> Just as we expect the security beauracracy to be capable of being flexible enough to work with citizens in changing the definition of bad-guys we must be flexible enough to work with their attempts to support the mandate given them by the people that they represent (which in the US is the citizenry - after all you voted didn't you? Well, so did your neighbors and if you disagree with the majority of your neighbors, take it up with them, change their minds, inform them of the consequences of their choices, print a newspaper, run a public access TV show, run for office, print pamphlets, run a website or simpley get out a real soap-box and stand in town center but don't blame the officers that are enforcing the orders given them by the people who were voted in to represent the majority of the voting citizens.) RANT OFF