Firstly, I said "perhaps deliberately, perhaps not" because I am not claiming that they intentionally wanted to provide security theater. I don't think that motive is relevant. I'm replying to a specific statement to explain that there is a benefit, even though it is intangible. Of course there are other bad effects, like inconvenience to travellers, and other good effects, like providing stable jobs to otherwise unemployably stupid Americans who live in or near airport-bearing cities.

In retrospect, I should have mentioned that last bit instead as a tangible benefit, but I only just now thought of it.