I agree but perhaps stupid is not the right word. The airline staff, especially low level, are not trusted or trained to think or apply their own reason. They're trained to be on constant high-alert and report anything that smells even remotely fishy.
It's not right that you have to hold your tongue in airport security or on a plane. But whether right or wrong in the moral sense, it's prudent to avoid alarming the staff if you intend to make your flight.
>The airline staff, especially low level, are not trusted or trained to think or apply their own reason.
You're right... the fact that they are given arbitrary power without training or trust is more the problem than their judgement as individuals. Or perhaps, because they aren't trusted, their orders are to resort to extreme measures as a default response to certain specific behavioral indicators.
Basically, one has to be mindful not to use words that will cause people too stupid to parse the context in which they were used to be anxious.