Can you provide a link?

She doesn't resent the MST3K episode at all. She and her dad loved it.

If he had a little ambition, he could make money from his dad's movie by being a guest at horror conventions or B-movie convention and talking about the history of the movie.

The son is allowed to make a profit from the movie if he chooses to do so somehow but what he is trying to do is stop anyone else from doing the same which goes against the very definition of public domain.