According to Dan Harmon on his podcast, there exists a director's commentary of Zardoz where the director starts it off saying something like "hello, my name is [director] and I'll be the first to admit this one... kind of got away from me"
Well, I guess that as long as something is still remembered, it still lives on even if just in peoples' memories. So in a way Zardoz is going to live on much longer than most of us, who'll be forgotten in just a couple of generations
It's like pure concentrated essence of 70's. I actually really do like it too; like I said in another comment it's not what I'd call a good movie as such, but the ridiculous camp is part of the fun for me. What's not to love about a weird-as-shit 70's dystopian scifi romp that's like Elysium on tons of LSD?
It's, uh… it's interesting. I wouldn't call it a good movie exactly, but it's not terrible either – very campy, very weird, often funny without meaning to be, and clearly a product of the 70's, but it's a fun and ridiculous watch.
Lots of people say it's incomprehensible because they just focus on the weird shit (of which there is plenty), but it's a pretty standard "dystopian future where the elite live lives of plenty by subjugating masses who live in squalor" trope at its core. Like Elysium but made by hippies