Perhaps because they are suspicious of academics even in their own ranks? What you say is very interesting but I guess any insights into the Hebrew auxiliary verbs was the input given to Fred Franz from his Jewish scholar friend. (He was allowed to have friends outside of the org 'cos it was his org!).
There is yet to arise an apologist for the Watchtower beliefs who dare look into the literary sources of the texts. This would be a most enlightening development since for the first time the Watchtower would be confronted with the exotic courtly accounts and pagan myth which were copied to form much of the true origins of the Bible.
Nevertheless Furuli is an exceptional case but no one below the rank of GB is permitted to let their light shine brighter than their leaders.