This should not be causing indignation. I think most of you agree with Justice Oliver Wendel Holmes that:

The most stringent protection of free speech would not protect a man falsely shouting fire in a theater and causing a panic. [...] The question in every case is whether the words used are used in such circumstances and are of such a nature as to create a clear and present danger that they will bring about the substantive evils that Congress has a right to prevent.

(whether or not you agree with the decision in the Schenck case.)

I assume that the inappropriate jokes that are being referred to are related to people claiming that they have a dangerous item. We arrest people for making bomb threats (and we shut down schools in response to them), and I wouldn't expect any different at an airport.