It's more the positive examples I was going to refer to - Yaya Toure as a case in point, one of the most skillful, cultured and graceful footballers the English game has ever seen and what's the most common term used to describe him? Powerhouse. There's a underlying stereotype towards African or African descent athletes that they can only possess positive physical characteristics rather than technical/mental/cerebral ones. Therefore Sterling can be fast but not skillful, strong but not intelligent etc etc and people constantly assume what are in fact major strengths in his game (vision, positional and spacial awareness, ball control in tight areas) are weaknesses instead of using the evidence in front of their eyes.
Sané gets it as well, I've seen his control in tight areas cited as a weakness on here, only Silva and Yaya have better in the entire squad.