Everything is political. Want is and will forever be in the nature of humanity. Conflicting interests are inevitable. Right or wrong making white people feel guilty for the things their ancestors may or may not have done is politically advantageous for African Americans as a group. Reparations can not be reasonably approved by the average white american without first inducing a pervading sense of guilt in the white psyche. Do I make the argument that this is the ONLY reason to make these films? Absolutely not. It is a great way to make money. There is a large audience for it. These films also serve as reminders and reinforcements to African American cultural identity.
It is way too hard for me to believe that the film director of The Help and 12 Years a Slave made the movie not for the purpose of making money but to make all white people feel guilty. I can't believe that if these movies were not popular they would still be made.
I am a white person and I never once have felt guilty watching one of these movies and I don't know any white people that do. I actually feel inspired by them to stand up against oppression or research the events portrayed. Yes, celebrities are usually democrats, but the only reason Hollywood makes these movies is because they know that people will enjoy them and they can make money off of them.