We have to do it. Some of us have to do it in different ways. Doing small things where you can is all well and good but literally none of us are making a single impact in capitalism by making different choices about how we're forced to participate in it. Focus on tearing it down together rather than picking apart individual choices because those individual choices still result in participating in capitalism.
Well something I think is important to keep in mind is that the areas containing a lot of the poor whites have Dollar General (or similar stores) as their main grocer. "Food Deserts" are a rapidly accelerating crisis in middle America. Not to say your critique is necessarily incorrect, just that these are very complex issues with a lot of facets to include in our analysis.