This is probably the best summary I've come across, particularly the true believers vs functional burnouts bit.

The only thing I'd add is that many (most?) lawyers are not only fundamentally uncreative and arrogant, but also weirdly insecure. They pick fights with each other over meaningless minutiae, simply in the pursuit of "winning". This not only means they're a massive pain in the ass to deal with, and it's also where a lot of the unnecessary expense comes from.