I'm guessing here but it could simply be that any moderated forum is effectively censored, HN included.

In my experience almost all dead comments I've seen deserve to be dead.

Down votes are more hit and miss I find it depends on the crowd that are attracted to that topic. E.g. Microsoft submits seem to be biased as pro Microsoft etc. That may be where the echo chamber effect comes in.

Looks like people don't like it when you criticize their idols. People forget Paul Graham is in the business of making money. Ethics and morality are not a prerequisite. They actually start getting in the way once you reach a certain level of fame.