There is no evidence of critical thinking or questioning whether all these claims are correct. Even here on HN, people who challenge the conventional wisdom are voted down. And make no mistake, opposition to the scanners and stricter pat-downs is very much the conventional wisdom around here.
It may well be reasonable to conclude that the costs of the scanners are greater than the benefits. But please don't just accept everything you are told because it supports your conclusion. Intellectual honesty requires challenging evidence that favors your beliefs as well as that which opposes them.