I think one reason for its eduring appeal is because it was of its time; it came out when a large chunk of the population was fascinated by the idea of paganism

I was a large chunk of the population at that time. Since I have since put weight on I suspect my wife would refer to me as an even bigger chunk of the population.

Would love to see the evidence for that assertion.

And are you telling me the mason's don't sacrifice babies? Where is the evidence for that too...............

I believe it became a cult film because some films become cult films and this was one of them.

Definition of a cult film? Your guess is as good as mine - but it probably includes "students" somewhere in it....