Tyrod carried himself with class the entire time he was with the Bills, and some people are judged harsher because not everyone judges the same, its important to acknowledge the individual side of this. Every situation is different, and in the Bills case, they did not bench Tyrod because he was black, that was based on his play. And then they did the same thing with the white QB, benched him because of his play and decided it was too early for him to have played. They then followed through with their plan on the rebuild and traded a QB that they could get a 3rd round pick for and hung onto the cheap rookie whom they were going to give more time, and to fill the void until their raw 1st round draft choice was ready to take the field.
Now, are there stereotypes that exist that could be perceived as racist, probably. There is a stereotype that the RB should be someone that is black, and a stereotype that the QBs are white. But I don't think GMs/Coaches/Owners would sabotage themselves by taking a less talented player just because he is white. If talent level is close though, I could certainly see where they would be more likely to choose the player that fits the stereotype which is probably a level of racism is some eyes.
And I, like many here was an adamant Tyrod supporter, even before he got to Buffalo, I liked him a lot, but he always left us Bills fans wanting more from him. Eventually, like many others I realized he was not going to lead us to a Super Bowl, and was ready to give others a chance. I think it was very smart to trade Tyrod when we did because his stock would never be as high as after he led our Bills to the playoffs.