And isn't this just what we would broadly expect of a culture moving from primary orality into literacy? The old wisdom passed down through memory would be prized over the invention of the new.

Until the written tradition can be fully relied upon, originality wouldn't be prized the way it is in current Western culture.

We should expect writers to say (even if lying) that their material is based on prior sources and not created by them.

Of course perhaps the primary oral bards may have exhibited this pattern themselves and used their own creativity to embellish prior "close truths". Just how far did originality go in the bardic tradition?

Compare this with using written statements to actively tell lies in the opening centuries of literacy.