Teach creationism as an unscientific religious idea? Fine. Turtles all the way down, if you like. But, science? No.
Once again, scientific theory does not mean “wild-ass guess.”
A scientific theory is a set of principles that explain and predict phenomena. Scientists create scientific theories with the scientific method, when they are originally proposed as hypotheses and tested for accuracy through observations and experiments. Once a hypothesis is verified, it becomes a theory.
Evolution meets this definition. Creationism, arising mostly from stories written down by our bronze age ancestors, does not.