said by Maven:Why is cable management important? My computer runs pretty cool. Is it just for aesthetics?
Take it from the King of cable-mismanagement, you want to have properly organized cables to you can see where and how everything is connected, and you don't want your cables to obstruct moving parts like fan blades.
There's nothing more annoying than realizing you forgot to connect your front panel headphone jack, opening up your case to connect them, and having to shove aside a bunch cables while holding a flashlight in your mouth shoving the cables aside with one hand and snaking your tiny fp connector onto the header with sweaty trembling fingers.
Bonus points if you've had over six cups of coffee that day or a couple of beers before you start hooking this up.