I think there is a different argument to be had about whether the government should be providing security for what amount to private business.
That said, flying is still a private venture for all intensive purposes.
There are lots of parts of this argument that cut both ways for me. The government highly regulates the airline industry. I mean how many other businesses can say that 'federal law requires compliance with all crew member instructions'? But the government isn't requiring that i use the airline's services, so the government isn't forcing me into any situation where i have to give up my right to privacy. If i need to fly then that is a choice i make.
I think they government saw a need, because the airlines would not do it on their own. They (privately owned airlines) hardly maintained planes propperly prior to "the man" stepping in, if you recall.
The airline business is a private venue for certain. Our country's air space, is another thing all together. I think it's more about that. National security kind of stuff. Try flying a little plane and go far off course (you have to provide your flight path to fly, as I understand it). See what happens. First they will contact you on the radio to correct your path.