I've previously theorized (and Vidiot seems to make similar points frequently) that the org might benefit by intentionally pushing out the fence-sitters for this very reason. They won't do it by relaxing shunning, though. It does seem almost like they're trying to do this through their increasingly absurd doctrinal changes, appeals for more money and increased control at a local level.
Others have observed that the R/F are becoming increasingly polarized between the fence-sitters and liberal JWs vs the hard-core pioneers/elders/need-greaters. I see this as being in the long-term best interests of the cult - slowly shed the fence-sitters that aren't assets to them at all (slowly so as to prevent a large splinter group from forming that might attract some of the more zealous ones) and this will allow them to liquidate assets to solve their apparent financial problems.