As others have already mentioned, this is media sensationalism at its worst and its most shameless. The show purports to merely present the "evidence" for various doomsday theories and apocalyptic prophecies, without arguing for or against the views expressed. For the less critical-minded, this might seem like an honest attempt to provide an unbiased view of all the available information, and letting the viewer make up his own mind about the facts. But in practice, this seems to be the show producers' way of avoiding any responsibility for the accuracy or validity of the claims/theories they present.
A 45-minute TV program can't possibly present _all_ the information that there is to examine on any controversial issue. There's always a practical limit on the amount of information that one is able to convey in any given medium. This is a limitation faced by all journalists and documentary makers. And, in truth, most audiences don't want to be presented with every scrap of info pertaining to a topic, or they'd be inundated with useless trivia, unfounded rumors, or outright fabrications. Like it or not, the media is a filter for the information that the public consumes. It is their responsibility to perform this duty with honesty and integrity. That means doing thorough research and, most importantly, verifying the authenticity/verity of the information they present.
On any given controversial topic—such as apocalyptic themes in human culture—there's likely to be only a handful of genuine authorities and knowledgeable experts for every thousand quack jobs or charlatans. Correspondingly, there will be truths, half-truths, and blatant falsehoods told about each issue. It's the documentarian's job to filter out the cruft and present only the most plausible theories based on substantiated facts. It is NOT the media's job to present, both, scientific theories and conspiracy theories in even parts. Unfortunately, this program does not do even that. It seems that the producers at History Channel have firmly decided that the truth is not as entertaining (read: sensational) as unfounded speculation put forth by the lunatic fringe. So, like "MonsterQuest", "The Nostradamus Effect" dedicates its entire program length to presenting spurious/unscientific speculation and interviewing hack authors of books advancing such ludicrous theories.
Regardless of the show's disclaimer, by giving a completely one-sided account of the issues presented (shows like National Geographic's "Is It Real?" at least give equal time to scientists/skeptics) and always skewing the evidence to favor the most outrageous interpretation possible, they are in effect promoting specious and scientifically unsound theories and irrational thinking. Making this all the more reprehensible is the fact that History Channel tries to present itself as an educational network while it shamelessly panders to the lowest common denominator, making programs that discourage critical thinking and promote self-delusion.