This has nothing to do with a private business. This is a federal force acting under federal law. If I want to fly El Al, I am subject to their security that includes profiling and is very effective. Does that mean that I don't also have to be subjected to the federal government having some mouth breather inspect my bags for something they can steal? Of course not, since the TSA is not acting because the airline hired them to do so. TSA is funded by tax dollars. They are only acting because federal law requires it.
This isn't like a bar that hires an off duty cop to provide security. This is like the police stopping everyone leaving grocery stores and searching their bags in case they might find some stolen item. You would say "then don't go to stores. Stop eating, nobody is forcing you to eat."