I think that sometimes laws are made with vague language on purpose so that it can be interpreted later on. I think that this makes statues flexible because it can be interpreted according to the circumstances of that time.
I know that some law makers get annoyed with the vagueness of some statute language. It's not easy to try to figure what people meant, especially if a statute was made a long time ago.
But I think it has many advantages. It makes the statute applicable for the long term. A very detailed statute will not be applicable in every case and it's not possible to make a different statute for each circumstance. It's better, more flexible and logical to make statutes a little vague, so that it can be interpreted according to the case at hand. It leads to dynamic statutory interpretation. This is my opinion anyway.