I disagree with some of the assessments above. Morris Chestnut is actually a very versatile actor. I watched him as a regular on both seasons of "V" and he was brilliant. On top of that, he is amazing with action scenes and fight sequences--he would totally bring the level of bad assery needed for BP. Women of all kinds adore him, and as was mentioned, he's a staple in Black American films, so that demographic would certainly come out to support him.
And, he definitely has the look:
He's definitely not what I would choose for BP--I'd prefer someone with more true native African sensibilities, versus Americanized "Hollywood Black"--but to say he's not an "inspired casting choice" (if it proves to be true) would be incorrect.