Slaktivist has commented on this often when writing about the Left Behind series of novels. Here is an early example.
A more recent and personal example happened outside my office a couple of years ago. First, I have to set up the scene. One of our professors collects artwork, and occasionally decorates our hallways with some of these pieces, in order to give the space a bit more variety. During this particular time, he had put up a series of faces of famous leaders who brought positive change in the past century, with a single word below the person's face appropriate to what he/she had done. One image had Dr. Martin Luther King, Jr. with the word, "Dreaming." Another had Ghandi, with the word "Watching."
I expected Left Behind to ... invoke the apocalypse as a cosmic version of the Hypothetical Bus [i.e., "be ready, because for all you know, you could get hit by a bus tomorrow..."], urging sinners to repent because the end is near.
But that's not LaHaye and Jenkins' agenda. Jonathan Edwards famously wrote of the fires of Hell as a warning. L&J write of the Tribulation as a vindication, a confirmation of their own rightness and righteousness.
Their intended audience is people who, like them, already believe in premillennial dispensationalism. Their tone is the juvenile triumphalism of an adolescent semi-threatening suicide or running away: Just wait until I'm gone. Then you'll see. Then you'll be sorry.
There's a message here for "the unsaved," but it's not ... "get right with God, because time is short," but rather this: "Ha-ha! We were right and you were wrong! Have fun in Hell!"
I would suggest that this is not a very winsome or effective strategy for evangelism.
A particularly conservative and tactless PhD student saw that picture of Ghandi and announced, "Yeah! Watching... from hell!" I promptly informed him that, even if his theology on this point was true, the attitude was not.
There are lots of other examples. You seem them at parades carrying signs about how God hates a certain group of people. You see them in tracts where sinners are depicted in particularly gruesome punishments as a wrathful God kicks them down into Hell. There's a line somewhere between what might have been an intention of warning people against these practices, and falling into a self-righteous revelry at the eventual doom of the people you've spent so much time and energy arguing against. And these folks regularly cross it.
If we're really living up to all our words about love, and compassion, and forgiveness, then it should tear us apart that there are people who might not get into heaven because they do things that God has called sin. Reminding these fallen fellow human beings that "God hates them" (which I don't even believe is true) or that they're in for eternal torment (which I wish I didn't) is not helpful for evangelism, and makes us sound a lot more like Nelson from The Simpsons (if you didn't click that "Ha-ha!" link above, you should do so now) than people who care about the fate of the non-Christians in the world around us.