Good explanation there Ding
To really get the core understanding to why these endeavors happened by the leaders of the WTS. one should review what, why and how these prolific bible teachers taught and preached going back to their beginning of the late 1800's.
Belief in Christ's personal return to set up his earthly kingdom—premillennialism—has always claimed adherents, but few people in the mid-1800s imagined it would attract more than a handful.
Yet by 1875 a new kind of premillennialists called dispensationalism began to spread. Given the embarrassing recent history of premillennialism in the United States (see the story of the Millerites, page 31), its revival was nothing less than amazing.
The new premillennialism came to the United States following the Civil War, after flourishing in Britain among the Plymouth Brethren. One of the Brethren's most gifted teachers was John Nelson Darby (1800-1882), a former priest in the Anglican Church of Ireland, who developed a new variety of futurist premillennialism. He called it dispensationalism, after the division of history into dispensations or eras.
"These periods are marked off in Scripture by some change in God's method of dealing with mankind, in respect to two questions: of sin, and of man's responsibility," explained C. I. Scofield, who popularized Darby's system in America. "Each of the dispensations may be regarded as a new test of the natural man, and each ends in judgment—marking his utter failure in every dispensation."
Dispensationalists quibbled over the number and names of the dispensations, but most American dispensationalists followed Scofield's seven-fold scheme: Innocency (before the Fall), Conscience (Fall to the Flood), Human Government, Promise (Abraham to Moses), Law (Moses to Christ), Grace (the church age), and Kingdom (the millennium).
There was nothing especially radical about dividing history into periods. What separated dispensationalists from everybody else was their novel method of biblical interpretation.