Well, people ARE cheap!
Think about it. There would be nothing stopping an airline from making a private terminal, using private screening (if anything at all), flying to a private airport and taxiing into a private terminal, all outside the purview of the TSA and their policies.
But the traveling public will not pay for it.
I'm on a jet right now. Exit row, on our third drink service, live satellite television (for free), MP-3's, video on demand and fairly snappy Wifi service on an airline where when I land in JFK, I can fly to almost any major domestic and international city in the world, but if it's $1 more than USAirways, people will fly USAirways with none of the above amenities on this route.