Maintenance, whether proactive or reactive, enables the machine to produce. What do lawyers enable that decent people cannot accomplish without lawyers?
I am staying away from lawyers dealing with the government, as I have discussed in many other posts, government regulations serve only to inhibit/discourage productivity.
I will work under the premise that you believe that patents (intellectual property rights) are important.
Someone infringes upon your patent. Now what is your day job? You run your company, maybe even make the product you patented by hand, who knows....
You need to clear up the situation with the other person infringing upon your patent. This other person is much better looking, charismatic, and is quite slippery. Now you need to convince a third party (be it a judge or whatever, but in this world we don't need as much legal language or technical knowledge of patent law because there are no lawyers).
Your only choice is to step away from your business, and lose much money, while you learn how to argue against this guy. Figure out the best way to prove to the judge that you indeed have the correct patent background, ect, ect..
In a world with lawyers, this would of cost you $2000 (a measure of productivity), in this silly world, you took 2 weeks off from your company and it cost you $7000 dollars.
Also in a world without lawyers, the slick willy's that would have become lawyers would run around, breaking contracts and infringing on patents because they know they can argue well infront of a judge.
Believe it or not, some lawyers do actually have a tangible skill to convince people of things.
Edit: As you see in this example, the lawyer is acting as oiling the machine of patent law. Preventing people from stealing your patent, there by increasing your productivity (and society's productivity because there would be little incentive to invent if people could just steal it from you).
You live in a naive world where bad things shouldn't happen, I live in a pragmatic world where bad things that do happen and -(-1) =+1