$0.02
bigyabai is talking about utility from perspective of the owner or a hypothetical buyer, not concerned with the wider community.
HN is just a free link aggregator, you can't make money from it.
bookface is only accessible to YC founders, which means YC founders have given a chunk of their company away to access it (as a bonus)
You see, the network of bookface (and bookface its self as a part of YC) is more valuable than HN.