Origin and context give extra meaning and weight to content. That seems trivially true to me. If Paul Graham writes this then that means the topic is on the mind of someone influential and important in our community, thus it is worthy of scrutiny and thought, thus worthy of an upvote.

Hacker News is not some game where people compete to create content with maximum merit. It is a source of new content relevant to this community.

Thou shalt not take PG's name in vain.