Why should they mind? It doesn't matter. They do. It's their right, it's their choice, and you don't have the right to steal someone else's property because you disapprove of how they choose to use it.
The fact is that artistic expression and freedom of speech are handy fig leaves for those who consider themselves more intelligent or creative than the rest of us.
If there's a market for "clean" movies, get a camera, hire some actors and go make clean movies. You have that right. You don't have the right to create derivative works based on someone else's property without their permission.
I don't get it. What's being "stolen" here? After I buy a book, DVD, or other copyrighted work, it's mine to deface as I see fit is it not?