Why do you think the writers of the Constitution made it so vague?

In order to win approval of the three quarters of states required for its ratification, the Constitution was a product of compromise that, at times, used vague or imprecise language-take, for instance, Congress' power to "make all Laws which shall be necessary and proper" to execute its long list of duties. In other words, the Constitution can be adjusted according to circumstance while at the same time being morally correct.