some people are just naturally power-hungry, some people are just naturally greedy, and a whole lotta people (myself included) are just naturally lazy, and would not work to the fullest productive capacity (or some reasonable facsimile thereof) without a sliding scale of renumeration and/or the possibility of being fired if you don't work hard enough. "From each according to ability, to each according to need" is a beautiful ideal, but uh, what's in it for me?