If you don't make copyright contagious under derivative works then people can just change a few things to get around copyright.
Also, do you really want a world where big film studios can just adapt books of writers without compensating them?
Also, do you really want a world where big film studios can just adapt books of writers without compensating them?
I'm not sure if this is sarcasm, but just in case it isn't: I don't think anything is preventing people writing the stories in their hearts.
I do really want a world however where fans/communities can riff on and make derivative works of culturally relevant material without being legally nuked from orbit. The last few weeks have been amazing in the gaming world, creativity abounds and there seem to be no limits as to what we can redesign to our own whims.
They don't do it anymore because the studios just pay for the movie rights upfront. The rights are cheaper than litigation, in many cases the studios only pay $100k, which is why it is news when they pay more than that.