Scientists love big ideas--ideas that explain in a coherent way a big open question. Extinctions, for instance. Explaining the extinction of dinosaurs was caused by a meteor impact was definitely a big, and therefore intellectually attractive, idea.
Unfortunately, impacts are so intellectually attractive that they're called on to explain all kinds of things they almost certainly are not related to, like the end Permian extinction, the Paleocene-Eocene thermal maximum, and end-Pleistocene extinction of megafauna in North America. The suggestion impacts caused all of those extinctions is just a bit nutty and most scientists would agree meteor impact is at best an unlikely explanation for any of those events.
The general public, however, is not made up of scientists, and apparently the general public likes a big idea as much as a scientist. The problem, of course, being that without the background to critically assess a claim or recognize a reliable source of information, it's not difficult to convince non-scientists something unscientific is true. Especially if it's something that sounds good or is something people want to believe.
My rambling here is because yesterday in the seminar I'm taking from Jay Malosh, we discussed the idea that the end Pleistocene megafauna extinction was caused by a meteor impact--an idea popularized through a popular science book, legitimized by a paper published in a prestigious journal without a peer review, and an idea that's more than likely wrong. The problem is, people don't want to believe the most likely culprit (humans) were capable of causing the extinction of almost all the big animals in North America.
None of this would matter except that these situations make science look bad. Global cooling (which was popularized by a couple of articles written by a couple of guys who did not present the scientific consensus, 'cause there wasn't one in the 70's) gets brought up to me all the time as an example of "scientists not knowing what they're talking about," or "changing our minds." It's irritating. The science that makes it into the popular press is so limited and too often not rigorously described, so people get wrong impressions about what's going on in science. It doesn't help that most of what makes it into the popular press is controversial or new and sexy (and so more likely to be wrong). Reporting results that essentially validate our current understanding of things just isn't interesting enough most of the time, so even though the vast majority of science does exactly that (reinforce our current understanding of things) people seem to want to see science as constantly being shaken up or pushing new, exciting, unexpected boundaries.