One difference is a different degree of taboo. Another one, I suspect more important, was the timing.

Yes, those are two differences, agreed. My suspicion is that the importance ranks the other way, but you might be right.

, if you want to talk about controversial topics, don't start by shocking everyone. (Unless it's a "door in the face" technique

Agreed, including the caveat and a few other caveats in the same vein.