I'm not talking about the system. I'm talking about your morality. If you say "A stupid person that contributes nothing deserves nothing." then you are making a moral statement that deems that person less worthy.
My premise is that all people are equally worthy of a good life. If distributing resources unequally helps everyone to have better lives through greater productivity then that is a justified utilitarian decision. But calling that pragmatic decision morality, and saying that people are "worth" more or less as a result, is what I object to.
And to address your points about "wife beaters", since you seem to think they are more obviously "less worthy" than others: No, I still think they are equally worthy of living good lives. They should be prevented from harming people, and if that requires a worse quality of life (i.e. as a result of imprisonment) then that is justified. But punishment for punishment's sake is just turning harm into even more harm.