Most people in health care understand and accept the need for clinical hierarchies. The problem is that we aren't usually prepared for them; nor are we given protocols for resolving the inevitable tensions that arise over appropriate care… Nurses cannot give orders, but they are considered the "final check" on all care decisions that doctors make, and we catch mistakes all the time…if the physician won't [recognize the mistake and correct it], the nurse's only fail-safe option is to refuse to perform the order.
Let's think outside the hospital for a minute. The three branches of U.S. government aim to provide each other with checks and balances, ensuring that one branch of government doesn't chug forward alone, reckless and unchallenged.
Although our government doesn't always function perfectly, we live in a democracy, not a dictatorship. There's no lone person pulling the strings, calling every shot. There's no one single-handedly declaring war or making it illegal to wear yellow on Tuesdays. The U.S. president may be the commander-in-chief, but he doesn't govern in a vacuum or operate alone.
In my middle school social studies class, the three branches of government were illustrated with a circular graph showing arrows pointing in a loop, not with arrows pointing down a chain of command.