This will stop. The web is quickly moving to the old network radio and network TV models, where talent rules.
Every major site offers content that can generally be found elsewhere.
What will distinguish sites from each other in the future is the celebrity talent with whom they have exclusive deals. But the gimmick is so easy, people think they can just plug-in anything and have it be priceless. Just because someone can type, doesn't mean they can write. Obviously the low cost availability encourages a democratic glut of inferior quality. I understand Spielberg and friends are firing-up a website devoted to student films, discovering new talent, etc.