People could just not use the airlines, find other methods of travel. If people weren't flying because of these things, how long do you think it would take for them to disappear from the airports?
People have been taught that security is more important than freedom. Who benefits from this, the companies that produce these machines, the developers of gated communities, the manufacturers of guns and weaponry, data mining companies, companies that develop security software and hardware etc etc etc. In the world of the paranoid and fearful, the security company is king.
I can see no difference between the people wanting these scanners in airports so that they feel secure and safe, to people buying guns and ammunition so that they feel secure and safe, its just a different enemy, one fears the terrorist, the other fears their own government. Propaganda is rife on both sides, missinformation is rife on both sides, and paranoia is rife on both sides. People who live in fear of their own government, are no more free than those that fear outsiders.
In the words of Billy Joel, "you can have security until the bitter end".