I'm only saying to completely remove security altogether with respect to how we treat the PASSENGERS. That is, when people walk into a plane let them be "protected" to much the same degree as when they walk down the street or get on a bus or a train. Protected by a little sensible thought put into how the environment is designed and a little faith in human nature, not at all protected by strip searches and behavior rules written out in minute detail and a legion of guards with uzis wearing camo on every corner.
In response to prior experience with hijackers, pre-9/11 "security" primarily involved disarming the passengers and training passengers and crew alike that they should act like sheep, exercise no judgment of their own and obey any commands given by hijackers. 9/11 should have sufficiently demonstrated the fundamental flaw with that approach - that it is brittle. It was perhaps worth trying back then, but it didn't work and we should try something else instead.
There are many busses in NYC where the bus driver is in a bulletproof compartment; he doesn't have to come out until/unless it's safe. One cannot reasonably expect to hijack such a bus. Planes can be similarly safe against hijacking so long as airlines take cockpit security seriously. Make sure the door is strong and secure, make sure the pilots can see OUT of it well when they need to - this might involve a bulletproof glass window - and make sure there are clear protocols such that nothing going on in the main cabin can force the pilots to come out. Let the pilots be armed as well if they so desire. Beyond that, we might want to encourage passengers NOT to be sheep, but it would probably suffice to merely let them exercise common sense. (The would-be shoe bomber and underwear bomber were ignominiously foiled by fellow passengers.) "Taking control" of a huge room full of hundreds of people is not an inherently easy thing to do and it's not clear it could ever happen again in a similar situation now that the risk is known. Given that ordinary technology and protocols and social institutions make controlling the cabin unlikely and controlling the cockpit nearly impossible even WITH the use of weapons, why bother searching for them?
There is a weird feedback loop in operation: we are unusually afraid of plane hijackings, so plane hijackings are an unusually good way to make people afraid. But hijacking is already nearly impossible, so we just need to stop being afraid of it. The solution to terrorism is to stop being terrorized. Modern security leaves people defenseless as it sends the message that they SHOULD be afraid; getting rid of security would send the message that the threat isn't so bad that we need to be paranoid about it. Paradoxically, this would actually make planes a less attractive target for terrorists.
There is no baby in there; it's ALL bathwater. It's dirty and gross and needs to be tossed out.