In many cases, these are family operations. There may well be two or three families, all related, that operate those businesses.
You see, unlike so many "white" folks, they believe strongly in all of the family working together, to help ALL of them succeed.
Their pattern is to all go together to purchase a business, all work to make it a success, then purchase another business, and so on, until all of them are doing well. They think nothing of working 12-18 hours a day, to make it.
There is no discrimination, they simply work together, just as so many immigrant families have done in the past.