There's no reason that all three shouldn't be taught.  However, creationism and intelligent design should certainly not be taught in a science class because they're not scientific at all.  It's not a question of "making up minds," it's a question of science class.\n\nItelligent design and creationism should and could be taught by parents or at Sunday school or during a religious studies class at school.  They're not science, but there's nothing wrong with that.  The fact that they're not science does NOT mean that they aren't true.
Instead of exluding discussions of evolution/creationism/Intelligent Design, why not teach all 3?