The Economist explains the thinking behind mindlessly idiotic government policies:
We must do something; this is something; therefore we must do it. Befuddled politicians are too often seduced by that beguiling syllogism
The specific policy it is discussing is the UK Conservative pledge to reduce annual net immigration, but it surely applies universally, from measure to "improve" aviation security, to increased use of prison sentences, to weapons like the dreaded ASBOs, which can turn wearing a hoodie into a crime.
I suppose that libertarians would prefer that, if a government insists on doing something, it does something futile and ineffective. But why the bulk of the population accepts such nonsense is a mystery yet to be revealed.