Dependence on moral inappropriateness
Debates about public (and even private) morality are curiously selective. This is often not because anything has been done which is illegal, "dirty" or clearly offensive, but because something has been done which does not quite fit. Appropriateness is an issue with real pain and real argument attached. The difficult point in many moral mazes is deciding when something that was acceptable has become unacceptable, or why something which was acceptable in one situation is unacceptable in another.