We have went back and forth on this, some, and before I dig in, I want you to know I appreciate your opinion on this.
The thing I would keep in mind with Bernie is he was out against TANF and the Clinton Welfare Reform Act of 1996 20 years ago. He voted against it in 1996, and wrote about it in 1997.
The reason "traditional" social programs don't work is that they were designed not to work. In 1996, Newt Gingrich and President Clinton came up with a deal to scrap traditional Welfare, and create TANF, that includes block grants to the states (which aren't always spent on social programs), a temporary nature, and most importantly, don't change with inflation.
So the Money for Welfare is essentially, static at 1996 levels until Congress decides to vote to change. The amount of money for benefits stays the same even as the pools grow (or shrink).
The work requirements have some inherent racism because the jobless rate is so much worse for Black Americans.
The programs don't work because they were designed not to work. I think you could design a program that DOES work (national minimum income or something like that), but this one isn't it.
I think you're right that there are certain structural differences that need to be addressed with legislation that targets people racially, even if they are temporary in nature or phase out slowly over some extended time period (50 years, say).
I think when people say that Bernie is better for minorities, or at least when I say it, I am specifically talking about the Clinton ties to Welfare Reform (which Hillary said was a great success as recently as the 2008 primary) and Sanders specifically saying that the law was immoral.