Are you asking why, in a system that its supporters claim is a meritocracy, it wrong for it to be easier for the rich to get richer than for the poor to achieve parity, given equal merit? Is that a rhetorical question, or are you about to argue in favor of the ethics of feudalism? Because bridging that ethical divide would take more than a simple hacker news comment.
edit: Ah, to more directly address you point earlier, and lay it out in simple ethical terms: withholding essential goods (housing) from others is a moral wrong according to consequentialist ethics systems. Doing things with a motivation of greed (profit) is also considered a moral wrong in intent-based ethics systems. The agreed upon axiom that they contribute nothing in return means there is no moral good to outweigh the moral wrong in either system, so in combination it is a net moral wrong.
edit: Ah, to more directly address you point earlier, and lay it out in simple ethical terms: withholding essential goods (housing) from others is a moral wrong according to consequentialist ethics systems. Doing things with a motivation of greed (profit) is also considered a moral wrong in intent-based ethics systems. The agreed upon axiom that they contribute nothing in return means there is no moral good to outweigh the moral wrong in either system, so in combination it is a net moral wrong.
This really shouldn't need to be spelled out.