This is just silly. If the local entertainment isn't very good, then people will find something better that isn't controlled by the Chinese government or shaped the rest of the Chinese culture, which is how you get Western values along with Hollywood movies. And you also get a culture that ignores censorship laws, because they are stupid, which can lead to ignoring other laws that are stupid.

I'm not saying pirated Marvel movies are going to bring down the PRC, but there's no reason to think that bad Chinese movies that no one wants to watch will help the party, either.