This turned into a really good thread! Some great perspectives. As a former claim adjuster and claim mgr, I can't stress enough how much of the disparity is caused by the attys. Having said that, when I first started as an adjuster in the 70's, I can still remember my boss telling me this on my first day: "All of the people you will deal with have larceny in their hearts. It is your job to figure out how much!"
You'd be missing two other responsible parties then, the person who suffered the loss and attorneys. Let's face it, any time we don't get exactly what we want, the natural tendency is to blame the other party. Also, attorneys run ads all day long talking about how the insurance company is going to try to cheat you on a claim.
Obviously, pain and suffering and lost wages is a bit more subjective than physical damage. But if you listen to the ads, you would think the insurance company is going to pay you a 10th of what you are owed. Fortunately I don't have first hand experience with it.