I think both of those are a great example of the fact that X-Ray + metal detectors provide sufficient protection in conjunction with alert passengers. Is the guy next to you trying to light his shoe or trying to set his pants on fire? Take him down.

More importantly, security is provided by catching would be terrorists before they even get anywhere near the airport. Because otherwise they can do a lot more damage at a crowded security checkpoint than they could with whatever explosives they managed to mix in their underwear. This is a job for intelligence agencies, not for the TSA.