This was such a great read, Simon! Excellent points. I have a deep love for terrible movies (as you already know, given my nostalgic love of the Twilight movies) so several of the movies that populate my "favourite movies" list are objectively awful.
I also loved your point about the Harry Potter movies because I've always felt torn with regards to my feelings about them. Love them to death, but they're by no means outstanding cinema. Well, except for The Prisoner of Azkaban because Cuarón's direction made me enjoy a book I found quite dull the first time I read it.