[zo1]

"This is why the current status quo has worked for so long: ISPs have no way to legally make profits out of "premium" traffic, so they (generally) don't apply outrageous QoS measures. Money is the only incentive, and removing that incentive solves the problem without the need for active policing."

And because they weren't allowed to charge extra for "premium" traffic, they essentially switched over to the over-subscription model in order to make profit. The tighter you squeeze, the stronger it oozes out the sides. And never in the place or way you wish it would!!