Government cruelty as such has been an explicit subject of American constitutional discourse since the founding - its in the Bill of Rights even. It comes out of a political tradition deeply suspicious of rulers using punishment to terrorize, humiliate, or vindictively hurt people.

Case in point Obama was deporting just as many people as Trump and it didnt require cruelty to do so. Which begs the question, why is a Gulag needed by Trump? The "cruelty is the point" argument is that 1) it isnt, and 2) they know that.