As a lawyer I have to disagree with you. Laws are not really written in a vague language. Laws are actually very precise, have specific parameters, and the language can be very acute... the area where you would have vagueness (actually a word, somehow) is when a person breaks that law on the very perimeter of its boundaries. That's when it becomes vague, as then a lawyer and judge take over in interepreting what the law says.
Now, are laws complicated? Absolutely.
WHY? Good question. Why not just have the laws in the books as: 1) Kill = a) life in prison; b) life with chance of parole; c) execution....
The very best answer is because laws and punishments could be written in simple language, but crimes are generally the most complicated aspect of the legal system. Severity, situation, personal records, jurisdiction history, motivations and ancillary factors... All these things create the need for laws to draw out every possible scenario, and the way to do that is to use extremely tight language that doesn't allow for loopholes, arguements over semantics, or any other wrangling out of the language. The more words you have, the more specific a law can be, and then the more difficult it is to get out of it.
Legal language is so complicated for one very good reason. Semantics. Remember Bill Clinton arguing over the meaning of "and"? That's case in point. So, laws are written to explain each concept to death through acute language.
I think the legal system de facto, not de jure, favors the educated over the uneducated, as it is just a difficult thing to do in general. Poetry also favors the educated, but I don't think that's anything vile either!
