Earlier quoted context omitted.
Majority of Black Americans are a distinct shared cultural group, like Hispanic folk, who come in many different pigments, also like Hispanic folk, who also tend to have an identifiable manner of speaking and protocol, also like Hispanic folk.
The problem is that while "hispanic" indicates a linguistic origin, "black" (like "white") indicates a physical trait - having skin pigment past an arbitrary threshold of darkness/lightness. You can be black and hispanic, or white and hispanic. You can't be a white black american, even if that accurately describes your skin and culture respectively. Also, you're problematically lumping all sorts of people who happen…
United States society has been problematically lumping people together based on skin tone for over 400 years; the GP didn't invent it today on HN. It's already been done and well-ingrained. If your skin is black, many people will treat you differently, to the extent that you may be subject to violence, many won't hire you, loans are more difficult to obtain, you'll experience stereotypes and racism regularly. In the end, rather than deal with danger and abuse every day, you end up living in the same neighborhoods, socializing with the same people, going to the same schools and restaurants, visiting the same websites ... to make your daily life peaceful and safe. As I mentioned in another thread, you can't even watch porn without encountering endless racist stereotypes.
As a result, while you may not think so and there are always exceptions, Americans with black skin share a lot with each other.
> slave-descended culture
What evidence do you have that this defines a cultural group (whatever that is)?
> We should be tolerant of criticism of this culture's ideology and practices.
Few people share your distinctions, so it's impractical. More importantly, it's impossible to distinguish criticism that is racist from that which is not. It's obviously easy, and often done, to say things that are arguably non-racist but critical in order to encourage and spread racism.
Also, criticizing groups seems inherently stereotypical. An at-will club, such as the Libertarian Party or local Linux User Group, is different. But being born in a neighborhood to a culture doesn't make you responsible or at fault for some stereotype which may have nothing to do with you (and usually are false and often racist anyway). Let's look at people as individuals, responsible for their own actions.
Finally, there's a lot of effort to create space for criticizing black people. Why is that important? How about we focus on the overwhelming problem, racism?