Your point is that being perhaps even particularly polite in situations like this would reduce the potential for trouble for yourself, but the author's aim was just to make a stand. It's actually a pretty noble goal, to do that on behalf of pretty much everyone else, who would just meekly comply.
I think something like "Good afternoon officer, how are you?" is even a bit excessive, although maybe it's become more like necessary when traveling in the US, which seems to be quite a police state nowadays.
What was it like at airports before 9/11? Exactly what benefit does the TSA actually provide? Why can't I bring a freaking bottle of water with me at pretty much any airport in the world anymore? -Why doesn't it matter if I volunteer to take a sip of my explosive liquids in front of the guards?