So What's the Point?
Oh. Wait. It's Summer travel season. Ma and Pa Kettle are on the road. "Look Ma, those nice young people from the TSA are making us safer. Gosh, anything to keep us safe from those bad people."
Meanwhile, cargo continues to be unscreened in any meaningful way, the airfield employees aren't screened in any meaningful way. Deliveries to the airfield aren't screened in any meaningful way.
So let's play this bit of Potemkin theatre out a bit...
Let's say that one of Bart's folks actually finds something -- gosh knows how -- but they actually manage to stumble upon a device (and I mean something much more sinister than an undeclared bottle of contact solution) in someone's bag (and clearly that "someone" will need to have been stupid enough to passively sit and wait to be searched). But let's say they actually get lucky. What does that prove?
Oh, it "proves" that random searches post-checkpoint "work". It also proves that checkpoint screening is ineffective or that airfield screening is ineffective, or that security checks of employees is effective, or that screening of deliveries is ineffective. What it would "prove" is that the whole system failed. But we already know that.
So rather than putting resources into "behind the scenes" work that might actually enhance security, the brain trust, once again, needs to provide a "show of force" (with emphasis on the "show") that wastes resources and provides no effective benefit in terms of real security enhancement.