> I don't think it's actually a pending question whether avoiding personal attacks makes people more likely to listen to a message.

That depends on the context. When you're talking about changing ingrained behaviors, emotional shock and awe can definitely be necessary and the shortest, most painless path to resolution.

the underlying incorrect assumption is that everyone will do the right thing, if only nicely and logically talked to. This is not true and obvious to anyone with experience managing large amounts of people, especially so when firing is not an easy option.