Jody sues Jerry over a few words in a will because Jody thinks she should get all of the property. The judge makes his ruling. Jody does indeed get it all in spite of the desire of the testator to split it evenly. Now, every trust and will has to have language added to cover this case.
Blame our lawsuit happy society. Every time a lawsuit is decided, language needs to be added to the documents to answer the questions that came up in the lawsuit.
It is also much better to define terms in the documents and spell out powers and responsibilities as much as possible. That way, the documents are not so specific to a particular state.