The most reasonable datings of Revelation have it being written around A.D. 95. John was the last apostle left alive by practically every account. Many Christians had perished under Nero, and more were being persecuted under Domitian. Jerusalem lay in ruins, and the Jewish nation was scattered to the four winds. The members of the first generation of believers who had lived through persecutions were now dying of old age. Jesus' promises of being near to return must have appeared hollow to many tired Christians, perhaps even John himself.
Then Jesus gives John a wonderous and awesome vision of terrible things to come. The visions involve the destruction of most of the Earth's surface and most of the world's people. The outline of God's return shown by Revelation doesn't reveal many new theological concepts. To quote Philander Johnson, it appears that the message of Revelation is "Cheer up, the worst is yet to come."
Nonetheless, Revelation is a blessing. Christians may not know when Christ will come, but we are meant to have as much understanding as we can that He is coming, and how He will come when He does. As He said, we may not know when the Thief is coming, and we will never know the day and the hour, but we can be ready. Revelation reminds us that our current travails are just part of the plan, that there is a plan and that God has set it in motion, and more importantly, we already know the highlights.
People interested in the End Times have often been guilty of obscuring it (To quote David Reagan, "I don't know what it means, but it doesn't mean what it says") or trying to make the entire exercise too specific or complicated. Revelation is a tool God can use to bless and comfort us, if we just let Him do so.