Journeyman,
Most of the comments so far have focused more on the camaraderie of working together, meeting other bros and sisters, group singing and other more social aspects
Spot on. This should tell us much about human needs. Sorry you didn't enjoy the dramas. One aspect of them I didn't like was all the over-gesturing. I found it unrealistic and it really turned me off. I understand that Ulysses Glass was the brainchild behind those early dramas. Evidently he demanded all the over-gesturing.
I suppose too that my knowing some of the local "actors" in the dramas made it more enjoyable for me. Every year the same congregation was used to supply the "actors" for them, and I was friends with some of those bros. and sisters.
All that said, they way they were produced, with the supposed actors not really speaking their own lines, but just mouthing them according to the recording, it created a ring of phoniness to the whole process. Real actors memorize and speak their own lines. That did not occur in these Bible dramas, so it added a degree of artificiality to the entire undertaking. Part of real acting is speaking one's own lines. As you put it, it was indeed miming.