You're not the only one with such a mentality but it truly is one of the great unfathomable mysteries to me. I get the notion of overdoing the repeat viewings thing and getting sick of a movie a bunch of times in short succession but the whole "I saw it, loved it, but have no desire to ever watch it again" for the majority of films is just something I can't wrap my head around. To me it's no different than refusing to listen to a great song more than once, look at an incredible painting more than once, go on a roller-coaster (if you're into those) more than once, etc.
Films are art. Films are experiences. Films are time capsules. The great ones tend to excel at all three and none of those aspects are "one and dones." I know there are some films that rely solely on some big twist like "The Village" and that once you see it you never need to watch it again but those are very few and far between, IMO.
Personally speaking, it's got more to do with time. There are so many movies and shows out there I haven't watched yet, that I feel "bad" watching the same things over and over again. It might be strange, but it's how I "work". At least it's not as bad as my sense of "obligation". I keep watching crap like LoT & Arrow out of it. I dislike them I find them boring, and weep for the lost minutes, but due to them being ComicBook shows, I feel like I have to watch them. Same goes with my monthly pull. Black panther is one of the worst books I've ever read, but I'm still paying 5 euros per month 'cause I like the character and feel like I have to buy it. I'm trying to let go of such fixations, but it ain't easy...
Back to the movies, the "I know what will happen" angle does play a role in my distaste for repeat viewings. But I also think the flick loses its magic" if you watch it one too many times. If you eat your favourite meal every day, you'll start to hate it. If you listen to the same five sons all day, you'll eventually get sick of them. Movies are the same to me. As I've said, there are certain flicks I can revisit once per month. Some I can revisit once every few months, and some I can enjoy once per year. And then there are some which I really, really like, but I wouldn't like to watch them again.