IMHO....
Before the internet and sites like JWD the only way a person with doubts could validate their feelings was to buy an apostate book. Now they can click through a century of material within an hour confirming all their issues. Knowledge is empowering (you wanna shout it from the roof tops), knowing you are not alone and online communities gives people strength to speak out. Also it depends on the personality of the eldership. If you have hounders you will have DFing, if you have lazy shadetree shepherds then the only way you will get DFd is if you start a scene during a meeting, even then you will more then likely just be encouraged to leave (become inactive).
Most of my Elders have doubts too, plus the temperment is pretty much shadetree shepherds now. Our last DFing was for planned adultery (they got married without scriptural freedom), was reinstated 2 years later. The only reason for them being DFd was because their best friends did the same thing a year prior and were only reproofed. Thus the Elders felt they needed to send a stronger message (even though it was them who sent the weak one).
My elders & I enterend into an agreement on my departure in June to the land of inactives. My only contact with them will be as friends, family & maybe a CO visit if we ever get appointed one that cares beyond his green handshakes, complimentary meals, or podium adoration.