Great film.... but Sal forgot how to run an American business.
The double standards in American culture are amazing sometimes...
I don't think there was anything unreasonable about asking Sal to put some black stars on his wall of fame. He was in a black neighborhood. Making money off of black customers in a black community.
The customer is always right, remember? Isn't that what we say in America? (Or does that not apply if the customer is not the right color? It's not about cultural sensitivity... it's about Sal having good business sense.)
Many Americans (of every color, including black) will get up in arms about the AUDACITY of Buggin Out wanting black people on Sal's Wall of Fame... but have no problems complaining bitterly that the person helping them on the customer support line has a strong Indian accent... or that the signs in their local bank are written in both Spanish & English (or Chinese & English) instead of being English-only.
If you're in a business, you cater to your clientele. Period. It's the American way. You only want Italians on the wall? Make sure you have enough Italian customers coming to that black neighborhood to stay in business and then you don't have a problem.
Where Sal went wrong is in thinking he could come into a community, run his pizzeria without customer input, and then try to get violent in response. Had Sal not threatened Buggin with a baseball bat for verbally expressing himself, he wouldn't have set off the chain of events that followed, the least of which was the burning of his pizzeria. Somebody was killed, remember?