It’s often asked, “what’s so bad about teaching creationism?”
One answer is that no has ever explained why it should be exempt from the normal rules about teaching nonsense & lies. We do not for example; teach children that the moon is made of cheese.
Another answer is that it is rejected by the vast majority of scientists who believe it to be bad science, & many mainstream religious denominations believe its biblical literalism to be bad theology.
Finally, it should never be forgotten that creationism is but one facet of a fundamentalist religious/political movement that is absolutely intent on forcing its backwards views onto our society.
Creationists are not just lone eccentrics with some slightly weird but harmless ideas about the age of the Earth, etc. They are well organised & motivated with biblical beliefs deeply antagonistic towards much of modern science (especially evolution), modern society & modern values.
This might not seem like too much of a problem in this country right now, because they do not have widespread support. However, have a look at the situation in America where their influence is growing.
Science and the First Amendment
"Evolution is just the tip of the iceberg or, as the creationists put it, the leading edge of "the wedge." The wedge they are seeking to drive through the heart of American democracy. The lies about science are not limited to evolution. Every day more lies about science seep into public consciousness. Lies about stem cell biology, lies about global warming, about clean air and water, lies about sexuality, about conception and contraception, lies about the effects of hurricanes on metropolitan infrastructure." - More
Creationism. Intelligent Design. Faith-based this. Trust-your-gut that. There's never been a better time to espouse, profit from, and believe in utter, unadulterated crap. And the crap is rising so high, it's getting dangerous. - More
Whenever I talk about the growing power of the evangelical right with friends, they always ask the same question: What can we do? Usually I reply with a joke: Keep a bag packed and your passport current. I don’t really mean it, but my anxiety is genuine. It’s one thing to have a government that shows contempt for civil liberties; America has survived such men before. It’s quite another to have a mass movement—the largest and most powerful mass movement in the nation—rise up in opposition to the rights of its fellow citizens. - More
The Christian Right, Dominionism, and Theocracy - Part One
Dominionism is therefore a tendency among Protestant Christian evangelicals and fundamentalists that encourages them to not only be active political participants in civic society, but also seek to dominate the political process as part of a mandate from God. - More
American Christian Fundamentalist Leader Calls For Global War
While the Western press is awash with stories, real and exaggerated, about 'Islamic fundamentalists', rarely is mention made about Christian fundamentalists, who, with their vast resources and close links with the current American administration, are a potentially more menacing threat than their Muslim counterparts. - More
And just look at their views on contraception
This then is the problem with teaching creationism. It is not only silly, illiberal, bad science & bad theology; but most importantly, it is also bad politics – unless of course you like living in a theocracy.
See Also: WHY WE MUST OPPOSE CREATIONISM
The theory of evolution is, of course, their first and most prominent target, and to destroy it creationists would gleefully tear down all of modern biology and genetics, as well as most of paleontology. But they target many other branches of science as well. To accommodate Noah's Flood, virtually everything we know about geology, meteorology and hydrodynamics would have to be tossed out. To make room for a young earth, quantum mechanics and other branches of atomic physics would have to go. To allow a young universe, astronomy and cosmology would be obliterated.”