But that's still saying to a group of people, please shut up so that I can enjoy this conversation. Now, I'm all for asking someone to politely keep to the parameters of the topic. If that means someone wants to keep the parameters to how their group/organization trains or does things, that's fine. I can bow out of the conversation.
I think that's what Janet is asking, that people *do* choose to bow out of conversations rather than restate certain well-known positions over and over again.
I don't think the request is to "shut up," so much as "we were talking about something else, and would like to continue to do so, please."