RMT was always very subtle in addressing controversial subjects, and never thrust them in your face. Also, radio is a much smaller forum then television or cinema, and out of the spotlight one has much greater freedom. The same is true of literature. Books have a much smaller (and more educated) audience then the other mediums, hence greater freedom. The novel "Lolita" eventually found a publisher and avoided being baned in most modern countries, but when it was made into a movie, the sexuality was heavily watered down.
At least that is my take on it.
And I definitely agree that people are much more tolerant of scandalous subject matter as long the practitioners of said behavior are seen to suffer from it. 