Was ancient Greek mythology particularly helpful for them to understand the world around them?
Well, I'd say their polytheistic structure made them more open minded and assigning reasons to events even if they're made up made them look for causality. Not that I'm an expert by any means but I'm sure it wouldn't stick around if it was useless.
I feel like the message here was more that the remaining userbase were bigots and there wasn't anything worthwhile there.