17 years or so it takes for evidence to become practice? That is, if it doesn't fall through the cracks... Could this writing for the purpose of impressing "very small groups of people" not be one of the main issues? Especially if these "small groups of people" really have no influence over what can actually be done with this evidence/research. They simply approve whether it is good/not good and it gets put on a shelf for time unknown until someone hopefully is looking for that exact information to inform their own research or evidence needs.
What good is research evidence if no one knows about it? Or it's written for such a niche group of people that the rest of the world is either unaware or can't read it because of clique-y jargon? This is a strong argument for the need for Knowledge Exchange/Translation people in the field to dig for this information and make it accessible so that it can be used and not just collect dust on a shelf.