Up until 1870 Harvard Law School taught that God was the origin of all morals and laws. That is when case law began to be taught when Christopher Columbus Langdell was appointed Dane Professor of Law at Harvard Law School. The reason this was done was because the previous method of teaching students were taught about the law and Constitution as solid and unchangeable because the law was based on absolutes given to us by God.
Langdell and the man who appointed him, Charles William Elliot, were both believers in Darwin’s Origin of Species and sought to remove God from the law and from the public. The farther men go from God, the more atrocities they are capable of committing.
Yes, case law alone allows for all sorts of interpretation, but more importantly, reliance on case law alone rather then the guiding principles of the Founders is one of the surest ways to institute and enshrine the rule of men.