Spiritually speaking, Why don't evolutionists allow creationism to be taught in school?

I am not saying that evolutionary theory cannot be taught. But this theory starts with umptions that leave God out of the equation. To be fair and balanced, to be truly scientific and look at all possiblities, Creation science should be taught as well, right alongside evolution. What's the matter, atheists, afraid Creation science will destroy evolution in the clroom, if both THEORIES are honestly taught?