I think this rule may have always been fake when anyone with even a little bit of power did it.
Of course it's unproductive to start from assumptions of bad faith, which is a fair point. Bad faith requires evidence of intent, stupidity doesn't.
But there are still situations where bad faith is a reasonable hypothesis to test. And some negative actors are clever enough to operate deliberately inside a zone of plausible deniability.
What is the adequate explanation via stupidity in this case though? If there is one that sure maybe we should lean that way without further evidence.
A subtle distinction, but I'd flip this as "malice is incompetence".