Thank you for the question on textual criticism, “Have any possible explanations been put forward as to why the early redactors of the Hebrew Bible didn’t do more to make it consistent?”
As I read the question, one has to define the distinction between copyists and redactors. Copyists are not redactors. Whether in the Old Testament or New Testament writings, Jewish or Christians attempted to copy the Scriptures as accurately as they can. Copyist would make copying errors, but as a general rule copyists do not insert their own interpretation of the text. Redactors deals with textual criticism, questioning the authorship, the date or even the content of the text. They give their interpretation of the text.
As one already knows prior to the discovery of the Dead Sea Scrolls, redactors question the accuracy of the texts or noted the differences between parchments and scrolls. With the Dead Sea Scrolls, scholars can now compare the writings between the 100 BCE to 100 CE or so. The differences are so minimal and have very little impact on the overall teaching of the Old Testament. One can read and compare the differences between the Scroll of Isaiah with any manuscripts. Copyists were not reckless in diligent for they believed that they were copying the very words of God.
The discussion of whether it is Isaiah 7:14of a main or a virgin may be debated. It is one word, not the whole chapter. A maid may be a unmarried woman or as some have suggested a married woman who hasn’t had a child. The point is that this woman will have a child without the sexual intercourse of a man. The discussion on the noun doesn’t change the meaning of the text.
Lastly, if the early redactors made corrections or make it more “consistent”, then we will have greater variant readings in the parchments and manuscripts of the Old and New Testaments. The copyists copy the text that was before them as faithfully as they can. We must remember that there were no erasers in those days so what was written was more or less permanent unless one wants to start all over again.
I am not opposed to higher criticism of the text for the correction of spelling and punctuation, the deletion or addition of word (s) so by comparing various parchments and manuscripts will allow us to come closer to the original autograph.
Summary: Copyists sought to copy the text before them as faithfully as possible, while redactors may try to correct obvious errors in a received copy of the sacred text.
-Kingston