Yes, they may be human, but the class logic they follow isn't. The cold calculus of profit subverts all their human emotions and empathy, allowing themselves to justify the most horrible crimes they are "forced" to commit. Even if one human refuses, the system ensures there's countless more behind them to serve as their replacement, ready to sink to new lows of depravity for material gain. In my opinion, the efficiency with which capitalism can strip a human of the best parts of humanity and encourage the worst is one of its most terrifying aspects:

Constant revolutionising of production, uninterrupted disturbance of all social conditions, everlasting uncertainty and agitation distinguish the bourgeois epoch from all earlier ones. All fixed, fast-frozen relations, with their train of ancient and venerable prejudices and opinions, are swept away, all new-formed ones become antiquated before they can ossify. All that is solid melts into air, all that is holy is profaned, and man is at last compelled to face with sober senses his real conditions of life, and his relations with his kind.