Right, and the result of this is repression of creativity. If you can't borrow on another's idea, expand on it, take it in a new direction (to use a common example, I'm thinking about Shakespeare set in different eras, highlighting themes more relevant to the current age than to the author's, etc) without being heavily penalized, then no one will try - at least not in the open.
It's easy to immediately assign the worst possible motives to the perpetrators. Those motives may or may not exist - maybe we can't know the insides of their heads. But the effects of these kinds of laws are the same; regardless of whether those who write these laws actually intend to repress free speech/expression and destroy freedom, that will be the result.