Asking questions will fail often enough ..... especially when the answer is the "truth" full of omissions.

And even if Qs & A-observations worked at airports, there are all those "targets" outside the airport.

Often enough, school-assigned police officers' "behavioral profiling" fails even when used in conjunction with a supplied list of "troublemakers". I see no reason why this would be a magic bullet when the "list" of "troublemakers" that airport security uses is already so messed up.