Although there may be some guilt feelings on the part of those who skip out between meetings, almost EVERYTHING the organization does somehow promotes guilt or fear.
It seems to me that the main reason for cutting back the public talk was that the WTS was afraid that too many people were losing attention and skipping out before the "most important meeting of the week", their WT Study indoctrination session.
I think the WTS could have accomplished its goal of getting more people to sit through the Sunday WT lesson by switching the order of the meetings, by having the study first. But maybe they wouldn't do that because they want that WT lesson to be the last thing on its members' minds as they file out of the Kingdom Hall.