I don't think anyone would disagree that the vast majority of content in any medium is tripe. And that doesn't assert that it fails to make "a positive contrib

I don't think anyone would disagree that the vast majority of content in any medium is tripe. And that doesn't assert that it fails to make "a positive contribution to knowledge". IMO "tripe" implies only: 1) it fails to achieve its intended end, usually through incompetence, or 2) it achieves its intended end, but it's aesthetically or ethically vile (like hate speech or child porn), or 3) it's a time filler, a mindless distraction, usually a palatable cliché. I think it's fair to say the vast majority of popular media belongs in classes 1 or 3. To deride such fare as "tripe" isn't unfair. Tripe has utility too. It's just bowel meat.