This is a great piece from the Guardian on why schools shouldn’t teach “both sides” of the origin debate.
The argument the ID advocates put, such as it is, is always of the same character. Never do they offer positive evidence in favour of intelligent design. All we ever get is a list of alleged deficiencies in evolution. We are told of “gaps” in the fossil record. Or organs are stated, by fiat and without supporting evidence, to be “irreducibly complex”: too complex to have evolved by natural selection.
In all cases there is a hidden (actually they scarcely even bother to hide it) “default” assumption that if Theory A has some difficulty in explaining Phenomenon X, we must automatically prefer Theory B without even asking whether Theory B (creationism in this case) is any better at explaining it. Note how unbalanced this is, and how it gives the lie to the apparent reasonableness of “let’s teach both sides”. One side is required to produce evidence, every step of the way. The other side is never required to produce one iota of evidence, but is deemed to have won automatically, the moment the first side encounters a difficulty – the sort of difficulty that all sciences encounter every day, and go to work to solve, with relish.