Sure anyone could be hit by a car tomorrow. But why do we even bother to have education and laws? Why police officers and firefighters? Why EMT and doctors? Why don't we just let everyone die if there is nothing more that we could do?
If there is only a 40% of a chance that a driver given a ticket will drive safer, then there is a 40% more likely for any individual to survive while crossing the street so we continue to issue traffic ticket.
If kids are 40% more likely to avoid smoking by educating them, we will do it.
If there is a 40% chance you will be saved from a gun shot tomorrow because of more effective, stricter gun control, you probably would support it.
If there is a 10% chance a solider will live after a brain injury, the EMT and doctors will attempt to save his life.
If we all say "well let's fuck it because we will all die", why do we even bother to save life? Why EMT? Just fuck the injuries and let them die. That's your logic. That's the logic we get: survival of fitness.
So, let's accept out ultimate risk that we will all die and let's move on and forget about safety. Just because we can't have a 100% success rate.
While the TSA cargo and individual inspection is not very effective, it makes an attack with bomb a few percents harder. It might open up other avenues (e.g. massive shooting at the waiting line) but we can't lose a few percents because tomorrow when shit happens, and when your loved one is dead, you'd be joining the army and shoot those mother fucker out. And then you will come out and say "I wish I had those stupid TSA did their job".