Deadlifts are quite possible the most useful (in my mind, tied with squats) since they target so many of the important muscles- glutes, hams, quads, lower back, traps..
I believe what deadlifts have taught me was how to lift properly, something everyone should learn- keep your back straight and dont arch your friggin' back- its impossible to injure yourself if you do this lift properly.
Maybe people "pull" their backs because they reach down or around an object and try to pick it up. You will not pull your back after doing deadlifts, or, at least if you think about lifting something properly.
Lower back is used for squats, deadlifts, even bench-press.
You cant go wrong with this exercise, the benefits are just incredible, and, as mentioned previously multiple times: Its a real man's exercise!