It is absolutely insanity. If the goal is to make it very unlikely, we were already there before naked scanners and confiscating water bottles. Using your own example of ever-shrinking Venn diagram intersections: The circle containing "people who just forgot to charge their phone" is probably 4 or 5 orders of magnitude bigger than any of the other circles you just told us to draw. Also the odds of the people building a bomb into an iPhone not being able to also make the phone look and act like an iPhone for some short amount of time is tiny.
Further, the act of blowing up the iBomb in the security line would be more dangerous and costly than actually blowing it up on a plane. Can you imagine? You'd get to shut down an entire airport and kill the hundred people in line. Back to my point, the continuing addition of rules at the checkpoints is insane. To think otherwise is willful ignorance.