If you don't have assets and don't have children and you are in full agreement on the issues, you are at less risk, but divorce (like marriage) can be one of the biggest financial transactions in your lifetime... you don't really want to get it wrong when you are dealing with your life savings and your children. I personally think that going into court without having at least spent an hour or two with an experienced attorney is a big mistake, but you are correct, you can fill out the papers yourself.
You said it yourself, MOST of the paperwork you can do yourself. What about the paperwork that you cannot do yourself? And, what if the divorce becomes contested or your wife hires an attorney? You should always look at the big picture and not the short-term benefit. If you do not hire an attorney and get yourself in a jam, hiring an attorney to get you out of the jam will probably end up costing you more than if you had hired an attorney from the outset.