Rutherford was a salesman.
Like any good salesman, he could use emotional argument to convince the unaware to buy. Rutherford also promoted himself as "President" of the WT Society and he was adored as such by the faithful.
By 1940, Knorr and Franz realized that times had changed. With a massive global war in full swing and later the fear of nuclear (Armageddon-like) destruction in the news, they capitalized on those sentiments. Knorr realized that his personality couldn't carry the Org. into the second half of the century. He changed the face of the WT ( just like the 'new' Governing Body is currently doing ).
He, Franz and the other writers became 'anonymous' and set about running the Org. like an international publishing company. I grew and grew and grew. Money flowed in by the bag loads and they invested it in real estate and the stock markets - around the world.
Their speculations payed off - big time.
ginger