It's "proper" usage is preface for a statement whose interpretation is ambiguous or easily misunderstood as disrespect, not as a "you're not allowed to be offended" preface for statements intended to be disrespectful.
What I was saying is that the latter use case is overwhelmingly the more common one.
My point exactly. Some people, Musk being amongst them for sure, are due zero respect. As such, using the phrase without showing or indeed having any respect is proper and correct use.
Well, its ACTUAL intended use (and the most common one) is to say basically "I'm going to criticise you, but it doesn't mean that I don't respect you as much as you deserve".
In some cases, including Musk, the amount of respect deserved is none and as such you can use the term correctly without respecting the person you're addressing at all.
What it "ACTUAL" says is "no disrespect" not "no unintended disrespect beyond the disrespect you deserve" - the intended use case is clarifying statements that are ambiguous or could read as disrespect, but are intended respectfully.
I do not agree that it's "intended" as a window-dressing disclaimer for open disrespect. Even if you personally feel that the target deserves no respect - just have the balls to disrespect them openly and without dancing about the matter.
The word use is very clear: "with all due respect" means "with all the respect that is due". If you want to express respect whether it's due or not, you say "respectfully". You're the one who's trying to enforced your personal definition over the logical ACTUAL one.
Btw, I do not dance around anything myself. When using the expression towards someone who's NOT worthy of any respect, I say "with all due respect, which is none".