[falcolas]

Without copyright, someone will just take their output, cut out the ad reads and repost their output with their own embedded ads.

This already happens today (Linus with his tech tips is only one example); without the ability for creators to fight back, it would only get worse.

EDIT: That this is unpopular doesn't make it wrong. Even beyond the (currently) illegal reposting, there are lots of rights aggregators who pay viral content creators, and re-sell their content to TV channels (Chive TV, anybody?). The "pay creators" part goes away if you take away copyright.