Well, when you're working with a group of random people, it helps to have rules so that they have some motivation to work together instead of being a jerk and not getting punished for it.
And when you're devoting 20-60 minutes to a single match, it kind of sucks to have someone there ruining your time with no consequences.
EDIT: Also, you're saying it's going to kill the gaming world. Do other games have to follow these same guidelines or something? The only reason they would do that is if they work, which would mean, you know... they work.