The Star Spangled Banner was written by a white supremacist who owned slaves and thought blacks were inferior. The 3rd verse is about slavery.
Why should a black person feel passionate about that song?
You can love America and still call out the bullshit that goes on as well.
Just like always when a black person attempts to speak up against racism, people try to distort the message, turn it into something that it's not, and completely gloss over the core issue.
It's hilarious seeing the racist who used "veterans dying for our country" to mask their racism get shut down last night by the #veteransforkaepernick hashtag on twitter by people who actually served / currently served support him and understand that they're actually fighting for his right to do this.