>>There is, or used to be, such a thing as common decency. Public venue or not<<
The 1st Amendment is a harsh mistress. You you have to grit your teeth sometime.
I have always been ambivalent about “public decency” laws.
I am not saying you are wrong — I am just saying in general my feet fall in the “more freedom than not” camp...
She has the right to wear that obscene shirt. AA has the right to deny her service, and the public has the right to ostracize her for wearing it.
How do you think it has come to this?
Or are there no limits in the social contract any more?
It was the private airline, not the government TSA, who was the heavy here. They don’t have to let you take porn to view on board, for instance. A church wouldn’t have had to let her sit in the pews with that showing. Etc.