Security doesn't have to mean inspection lines or profiling.
It could mean guards walking around, like in an apartment complex or mall. It could mean people watching CCTV.
This could all be done by the airline. They don't want bombings just as much as you or I. The only difference is they don't have an incentive to create a regulation that forces people to subject themselves to embarrassment or harassment.
Where is the TSA's incentive? Justifying their existence. In one hand, you have an anti terrorist, governmental agency, which will always try to justify itself, and on the other you have a necessary expense for the airlines mandated by their public relations and to reduce bad press/events from happening.
