As an individual, you should have the right to access any information another person wishes to generate. AFAICT, Hacker News moderators are hiding posts they believe do not provide value to the site. This is fine, but you can still see a non-moderated feed using Algolia's Hacker News search website.
1) Using the "Show Dead" option in the preferences might be an easier way to see the raw feed. Click on your username to access this. I think this allows you see everything, even some things that Algolia doesn't (such as submissions from banned users).
2) You are right and not right that the "moderators are hiding posts". Stories are usually flagged and killed by individual users, and not the paid moderators. But obviously the moderator (singular) allows this to happen. Dan (the moderator) also chooses which users to ban.