Because you can't host them on thoughts and wishes alone. The capitalist system with its legal constraints is what created it, funded it and runs it.
And yes, hosting incurs costs, but hosting copies of content isn't "retelling" or "remixing", it's copying. And since we want cultural output, we're incentivizing the production by giving you exclusive rights to benefit from your creations.
If you believe that the terms are ridiculously long and should be drastically shortened, I agree. But rejecting the idea of copyright will just remove much of what is created. I don't think we'd be better off in that case.
You might argue that that which wouldn't have been created had there not been the promise of potential profit isn't worth much culturally, but in that case you shouldn't be worried about the copyright restricting access to it, much like you shouldn't be worried about a locked door denying access to an empty room.
I know, many people feel nostalgic for the internet of old before the unwashed masses joined and they wish to return to that time. I don't, I find today's internet much better, I welcome the technological progress and I'm happy that it is serving all of society and is no longer an elite-only thing. Sure, I get annoyed by Spam, Google flooding its index with SEO nonsense and people screeching on Reddit, but I find those to be minor issues compared to the advantages that we get from the internet. And I do believe that commercialization is responsible for most of the development since then.
On the other hand: why are these public goods services still hosted in infra/protocols exposed to western/us legal arm?