Do you want to try to build a startup today taking on YouTube knowing that the legal system is a complex mess and if you make any mistake, you'll be sued out of a company? Will any VC want to fund you in those conditions?
And what makes this website not a "content sharing service provider"? All the site does is share links to content. And since linking to content will now obligate paying the person you link to, hackernews will have to start finding a way to monetize just to pay for all of the linking it does.