Well no one needs to have anything. Having expectations based on what one knows about a black man's anatomy can be harmful if those expectations are not met. As a black man, I would steer away from dismissing the the reality that black men are bigger. The myth is that black men are hung like horses. That's obvioulsy not the reality. However, black men being bigger does hold truth. Stereotypes exist for a reason; they are not entirely made up. Many races, male and female, are sexualized for their uniqueness. Asian women are sexualized. Black men are sexualied. Black women are sexualized, etc. For example: are black women naturally more curvy with bigger butts? Yup! It's in their genes (haha). This is something that you can observe. Is this true for all black women, no, but just because some people are the exception does not negate the rule. It's not a myth that black women have thicker bodies. As for black men, yeah... we're bigger down there. But not like horses, lol! Black people have thicker lips, broader noses, thicker hair, [women have] thicker bodies (butts), and [men have] thicker cocks, etc. Blacks even have higher bone densities (look it up). This is just the way it is. Different races have different characteristics. Nothing wrong with that. I am ~8in myself. This is not to say that this is common for black men, or men in general. Just saying, odds are, I encounter more black men with larger cocks than any other kind of men. But the difference is nothing to get all excited about. 5", 6", 7" all the same to me, really.
Also, porn will always perpetuate "myths" and sexualize certain kids of people. It's porn. It's fantasy. No need to moralize porn.