That's because Jews in America are not as diverse a group as black people are. They are a smaller collective, and for the most part their experiences don't deviate that much. However, there are issues where we do see disagreement within their community. America's interaction with Israel is an example.
Also, keep in mind that we know a lot more about black disagreements because we are black and privy to internal discussion. We don't know how much dissent there is among Jews that simply happens in settings that we aren't present. Now if you're talking about what happens in the public eye. I think what we see is less less because other groups are more on code and more because black people tend to be more vocal in general than others. Black people have no problem airing out grievances with or without organization. You just don't see that as much with other groups, so you're not going to see their disagreements.
