The March 1970 KM reported on how well publishers were doing in dropping unproductive bible students so that others could "benefit" from receiving a Bible study in the short time remaining. The article "Become 'Intensely Occupied with the Word'" in the "Presenting the Good News" section said on page 4:
A little over a year ago we were introduced to the six-month home Bible-study program. We immediately grasped that this would be an additional effective method to help get the work done in the short time remaining.
Now reports from the field show that Bible studies are being discontinued as publishers realize that the student is not making progress. This is entirely proper. There is no reason to spend our time with those who obviously are not really interested in doing something about the truths they are learning. Some publishers still ask, "How can I know whether to discontinue the study when they appear to be interested and still are glad to have me come?" The answer is that we discontinue studies when it is apparent that there is not the appreciation for the truth that there should be. There might be interest in continuing to take in knowledge. But is there appreciation for the knowledge already taken in? Appreciation for Jehovah and the truth is demonstrated by deeds...
Apparently the matter is being taken seriously by the brothers, because circuit servant reports show that many publishers unhesitatingly discontinue studies when the time comes to do so.