[nullc]

Race, gender and age enjoy stronger legal and social position as protected classes than economic standing, political orientation, or education does.

As a result one way to fight for justice for the economically disadvantaged is to make use of the racial correlation.

The fact that an issue disproportional impacts the poor and as a result disproportionally impacts people of particular races can also contribute to race-specific second order effects. For example, evidence strongly suggests that some race are treated particularly harshly by the judicial system in the US, leading to increased rates of convictions and harsher sentences-- so having backdoored phones is quite possibly a double whammy, causing additional harm that another population with the same devices wouldn't experience.

Ideally we'd also protect the economically disadvantaged from things like this without needing to reference a particular subset of victims, but when someone advocates for the welfare of others they do it in the world we actually live in, not the world that we would ideally have.