Conditions in ghetto areas make it more expensive to operate. Higher insurance, more shoplifting and internal theft, you have to pay good people more money to go there, etc.
But the chains CANNOT charge more to cover the increased costs, or they will have a local news reporter-slut doing a segment on why the same can of corn costs $x in white-area store and $2x in black area store (answer: "RACISM!")
What it will take is for you privileged weypepo to go out of your way and shop at these stores.
Get out of your comfy suburban neighborhoods and come to the high crime districts and MAKE these grocery stores sustainable.
It has always worked before, right?