I think they are following a strategy of introducing change to try and keep people motivated. The carts, reduced pioneer hours, special campaigns and now the changes to reporting to make pretty much anything count simply paper over the cracks but are enough of a veneer to keep people chugging along, especially in areas where growth is negligible.
For areas where there is still greater growth then all the above methods are fine as well but if people are more open to a Bible study and less willing or capable of questioning what they are learning then the added benefit is that the publishers feel motivated simply because people seem interested.