That's not free, that's paying for it in a different way.
I do think the internet should be free, but how we sustain that is a pretty viable question. APs need to be installed, configured, and monitored. When spaces grow, APs usually need to be reconfigured or moved.
I know that airlines are fairly low margin businesses, based on what I've read from the recent bankruptcy stuff. I am curious about who owns airports and what their margins look like.