I get exactly what you mean, and it's been my position too for the longest time. And of course, from a "scholar"'s point of view, I could argue about why/how Pasolini / Jodorowsky did great stuff (for example, my thread about Panic films), or that TND is "objectively" more complex both in narrative structure and in themes than The Substance, or, to hit it through the park, that Bud Spencer never did a film on the level of the worse of Ruiz's filmography. None of that would really be objective, though. It would be, as I said, from a scholar's point of view. I think that's exactly what I was missing from Jauss' theory: yes, my field of experience will determine what I receive as pleasant, original, or brilliant (if it manages to stray away from the banal and retain its meaningfulness), but this horizon of expectations is everything but objective and will differ from one reader to the other, no matter their prestigious academic level or experience.
For sure, I'm for the Hippotomaus is an "objectively" better (and certainly more pleasant) experience than On Top of the Whale for most viewers (and I say that confidently without having seen the Hippo one - I just looked through Spencer's filmo and thought it was a great title to oppose to Ruiz's Whale film). I'm pretty sure most people wouldn't even get through Ruiz's film. I would not agree, I could write an essay and back it up, but there still would be no objectivity either way. We tend to think our subjectivity, based on experience, readings and studies, is closer to the truth of what makes a great film, or a great work of art, but in fact, there is no measurable determinant other than consensus, which is determined by a selected group that mostly agrees with itself (and is often fabulously wrong).
Still, I think you are right when you say Carry-On is a smelly pile of garbage that will soon be forgotten. I can't help myself.