Welcome back to "Doggerel," where I ramble on about words and phrases that are misused, abused, or just plain meaningless.
One of the irritating grounds I've often seen woos retreat to when they fail to defend their pet woo is "What's the harm?" Some forms of woo are obviously more harmful than others, but each has potential.
1. Death: Thought I'd get the big one out of the way. Alties make up, in my opinion, one of the worst subsets of woo, and they can go far enough to convince a person to give up their proven medicine in favor of a useless treatment. This is especially prevalent in cancer quackery. Additionally, religious woo often fosters an environment where people can be convinced not only to kill themselves but others in the process: Where there are promised rewards for blind obedience, there's less incentive to step back and consider the morality of an action. You can be sure the comments will have a lot of discussion about the various aspects of this bit. Combining the two is faith healing, which is as dangerous as any quackery, possibly more so, since those with crippling conditions are often asked to jump out of their wheelchairs and risk further injury.
2. Reduced quality of life: Even when quackery doesn't lead directly to the death of a patient, it can lower the quality of life. That link above provides an anecdote, for the sake of example: A man, using a mail-order treatment tried to treat his basal cell carcinoma. The result: The tumor kept growing, disfiguring him over the course of 15 years before he died. He would likely have had it much easier if he used proven medicine.
3. Social harm: It's my experience that woos are among the most unpleasant people I've ever had to deal with. Despite their accusations against skeptics, they tend to be incredibly closed-minded, and are often intolerant about the idea of differing views. Having a conversation with a woo can be like navigating a field of land mines. With normal people, you can have disagreement at multiple levels of intensity. I could have a joking 'argument' about Picard being a better captain than Kirk with some fan I bump into, or I could go to one of the really deep Trekkie sites where every thread moves faster than Godwin could ever predict. With woos, (again, in my experience) however, everything is either polite agreement, or a mad dash to the flamethrower so that they can immediately start flinging inane, irrelevant accusations, lying about our positions, and then accuse us of heating up the argument. I can easily see this leading to the destruction of friendships, and on the religious front, many people cut off relationships once they learn a friend is an atheist.
4. Psychological harm and cynicism: Woo leaders often demand complete trust from their followers. They usually have some empowering, uplifting, though unrealistic philosophy, and anyone who opposes it is evil. When people start bringing in contrary evidence, the woo's reaction is not to change his stance, but to rationalize the evidence away: It was forged by the Men in Black. Sloppily gathered personal experience trumps careful investigation because the woo leader says so. The people presenting the evidence are being paid by the Bad Guy. Soon, they've constructed a vast, global (or even intergalactic) conspiracy so that they can claim they're being persecuted. All of this rampant cynicism is preferred over the idea that the leader could be mistaken.
5. Economic cost: Woo isn't always free. Beyond the obvious payment for "services," there's also the cost of time and opportunity. I can think of better things to do on Sunday mornings, for one. If you've got some terminal disease and are trying the "no stone unturned" approach, money and time you spent on useless herbs could have been spent on some new experimental treatment just cleared for human tests or something like that. Everything that you use for woo could be used for something useful instead.
6. Societal harm: One of the great downsides to democracy is that idiocy can still be popular, and thus stand a better chance of getting on the budget than its merits would allow. That's taxpayer money being wasted when it could go towards legitimate research.
Smaller forms of woo, like reading the astrology column in the newspaper, may not be immediately harmful, but it can eventually lead to the above if you're not careful. After all, woo isn't just a set of crazy beliefs: It's a reckless way of thinking.