Well I'm sold. Serves you right for looking suspicious in front of the Looking-suspicious Detection Officer!
And now they do and you complain anyway. So - what's your preferred method of screening people?
Both times it was portrayed as super amazing (low hassle plus high security) precisely because they used behavioral detection techniques.
The TSA version is a guy walking around the terminal engaging people in conversation and looking for things like "micro-expressions." (which are themselves a farce)
Putting aside the obvious falsehood ("every time") there's obviously a little critical analysis required to differentiate between people who are nervous because they don't like getting airplanes, people who are nervous because they're about to miss their flight, people who are just generally anxious, and people who are nervous because they're about to blow up an airplane.
That's the problem with USA security, against say the one in Europe or the middle east (I think Israel has very good trained anti-terrorist immigration officers): In these other countries, there are a lot of darkish-skin people, so they really have to learn how to profile someone who is up to something. In the USA? I guess the majority of time they just use the skin color... and that's why they get a lot of false positive, and /very/ annoyed people.