Asserting control over the afterlife (or lack thereof) is one thing. JWs control the now via the shunning policies, their strict control on information flow and strong phobia indoctrination.
Exactly, Armageddon is not really that scary when you think about it. Most non-religious people believe that we will all die eventually anyway. So whether you die at Armageddon or not makes very little difference. JWs have been ingrained with the idea that they are special but only because of the organization. They fear that if they leave they will lose this special status and become like other "worldlies". They will also lose their JW family and friends. These JWs will reinforce the idea that they have lost something special and are now worthless until they return to the org.