Taken the genre as a whole, black men hardly ever get to be the resourceful, confident, self sufficient, straight, heart throb leading men in the way that white men have. When they do cast a black character in those roles, they go to black women most of the time. Even when we do get to be the hero of the story, we have to share the spotlight in ways our white male counterparts don't have to. A great example of that is Black Panther. Technically, he was really just the muscle. Contrast him to Iron Man's, Cap's or Thor's first films.
We're just tired of that way of doing things in genre TV and film.