1) I understand that the issues compared are different, but I posed a hypothetical scenario of how the issues at PH can go beyond just having a tightly-controlled growth engine for companies PH likes. PH has no ethics-policy (that we know of) and nothing stops A16Z from telling the mods that any product related to A16Z-funded-firms should get top spot at PH.
2) Fair point, but that does not mean we should not try something new :) Afterall, HN is/was an experiment to address the issue of community-decline due to growth. Also, the decline in "Show HN" (almost like second-class-citizen-status) and the fact that PH exists, indicates to some measure that a "launch platform for startups" is relevant.
3) I have added some more details about myself as well as a disclaimer of affiliations (none).
4) I intend to build this alternative with community feedback and as a Proof-of-Concept. I will not dictate "how things go", which is why I value community-feedback so much.