The Usefulness of Dispensationalism

Someone in a discussion forum recently asked if dispensationalism was a useful system of theology. I replied by saying that I believe dispensationalism can be useful in the following ways:

It can be a useful tool for manipulating millions of people into supporting a Middle Eastern country which has nothing to do with the Israel of the Bible. It can be a useful tool for duping people into believing that the current world political and military events are expressed in the book of Revelation, and that Armageddon (misinterpreted literally as a great military confrontation) is soon to occur, which can further be used to help muster support for military expeditions in the Middle East (it seems that some would have us believe that all of America's military actions are expressed somewhere in the Bible). It can be a useful tool to help convince people that they are going to be raptured any day now and so nothing that they do in this world really matters all that much (other than getting people to "make decisions for Christ"). It can be a useful tool for setting aside the prophecies of God that were either fulfilled in or are applied to the church. And it can be a useful tool for revoking the promises made by God to all believers throughout the OT Scriptures.