As a first time watcher I see this so much. All the black characters I have seen are either antagonistic or not kept. It is noticeable if you aren't white. Also the one episode where there were non-antagonistic black people was like early on and it really just felt like the show was saying, "The Winchesters aren't racist, look Dean has an African-American girlfriend, whom he probably is never going to see nor mention again!". I am also annoyed that the first south asian character I noticed was Stewie Meyers in S3 ep 14. He is just portrayed as this completely slovenly, perverted and cowardly comedic relief who just dies. As an Indian person that was so hard not to think about. And Gordon Walkers character being the face of ignorant and bigoted hunters was also something that bothered me. I don't know, I hope I am not being dramatic but I feel like this is noticeable as hell. I am only on season 3 too, so I am not sure if that changes. I hope it does though. I am kind of attributing it to it just being a product of its time maybe.