What should be taught in schools, and how, is a matter of endless debate. Here in Spain, Catholic religion is part of the school curriculum; the Catholic bishops (who are appointed to their posts by the Vatican) appoint the people who teach religion in public schools, and taxpayers pay the salaries of these teachers. In the US, Biblical literalists are successfully pushing the teaching of "intelligent design" alongside science in biology classes. Deepak Chopra, a "foolish old poop" from the political left has his own anti-science ideas. There are no limits to the debate.
I think the crux of problem lies in the decision-making process. Who must decide about the school curriculum? In both the US and Spain we have central planning of education at several scales from school districts to the whole nation. A limited number of officials make the nominal decisions at each scale, but they hear to constituencies. Members of those constituencies actively participate in the public debates or just state their opinion through polls. We expect officials to make decisions that are popular. That is how democracy works.
We don't want democracy to run every aspect of our lives. I don't want a popular vote to decide where I buy my groceries, or what time I go to bed. I prefer to decide for myself. When deciding about matters of my life I prefer to follow my own opinion than popular opinion. What is wrong with popular opinion?
When telling me how to run my life, other people may be more interested in their own well-being than in mine. Most people do not know important details about my life and, in fact, have little interest in knowing them. And people may hold irrational beliefs about certain matters of life because holding those beliefs does not harm them in any way. Let's examine the latter problem more closely.
Most people who agree with the beliefs about biological evolution championed by Deepak Chopra or the Biblical literalists do not, for that fact alone, live better or worse lives than people that are educated in science. Holding those beliefs does not harm their health, finances or love affairs (well, I'm not so sure about the latter). Indeed, it is perfectly reasonable that we all hold irrational beliefs provided they do not affect our personal lives. We take delight in holding and expressing bizarre beliefs when that does not harm us in any practical way. A few people even make money out of it.
The problem arises when we impose our irrational beliefs on other people. What is benign to ourselves may be harmful to others. I consider that spending time at school learning intelligent design, astrology, Catholic prayers, tarot, homeopathy, or the natural history of fairies, instead of learning science or just playing soccer with his friends, would be harmful to my child. People that believe that anti-science must be taught in school do not bear the costs imposed on my child and thus have little incentive not to harm him.
How can we get out of this quagmire? My proposal is to abandon central planning and embrace decision-making at the individual level. In the case of children's education, let parents decide. Instead of parents having to pay for public schools, let us pay the private school of our choice. If each school were free to decide on contents and teaching methods, parents could decide the kind of school education their children would receive. Biblical literalists, New Age cranks, and everyone else could decide freely and could not impose their ideas on other people.