Why? Assuming this is not a rhetorical question, it follows directly from the core authoritarian principle of Conservatism in the U.S.: Moral Hierarchy. That is to say, Those who rule are privileged above those who serve, and this is the basis of a ranked ever-swelling staircase of privilege.

Any action or policy that supports the hierarchy is divine, and whatever threatens the hierarchy is evil. Free food, or food as a right, is antithetical to Conservatism because it diminishes a key point of leverage held by rulers going up the chain. When a person is fed, they are less inclined to honor the privilege of their supposed rulers. When a person is truly hungry, they are highly motivated to submit, and even to support the hierarchy that provides them with any limited access to food.

In this philosophy, the ROI of free lunch is negative. The same argument applies to most forms of welfare.

The cruelty is the point.