It's not popular being a naysayer. I often hear complaints by people who may or may not themselves believe in various pseudo-scientific theories or outright crackpot ideas, and the consensus seems to be that it is not polite to debunk ideas that are near and dear to people.
Not polite, maybe. But necessary.
We have a civilisation built on science and technology, and we're having a population that gets more and more alientated from the hardcore of reality, believing all sorts of wacky things: creationism, UFO theories, homeopathy, conspiracy theories, astrology, you name it. Ideas lead to actions. If you have a population of irrational and ignorant people, they make irrational choices most of the time. Like refusing lifesaving medical treatment for crackpot ideas or prayer or whatever.
A lot of serious decisions comes down to knowledge of some complicated facts. Think environmental issues, for example. People making these decisions are mostly lawyers and economists, who don't have a smattering of an idea what it is about, and thanks to the negative rap science gets in the mainstream media (journalists, for one, are almost always scientifically near-illiterate), politicians are less and less likely to listen to scientists.
I think, in fact, scientists should say loud and clear what is crackpot ideas and why they are crackpot ideas. Critical thinking is a crucial quality in the modern world that is more and more lacking of it.
