In addition to what everyone else said, why lawyers? (Also, why doctors?)

Like, I get why a naïve opinion might be "the more engineers, the better" on the simple but attractive theory that more engineers = more stuff = better for everyone.

But what's the even simplistic theory that leads to "the more lawyers the better"?

And surely even a simple theory says "once you have enough doctors to provide healthcare to everyone, you're kinda done with doctors."