I don't see this is completely weird. If I was designing the news feed, I would give way more importance to personal posts (especially photos) than non personal posts, as I would like to preserve the personal nature of Facebook and not pollute it with non-personal info.

However, if a business (a non personal entity) wants to gain entry (and potentially pollute the experience to some extent), there is a price they have to pay. And that constitutes facebook's business model.

The fact that they introduced "Free" business pages which allowed free entry to people's news feeds before ads has skewed the perception of their intentions. But if I were to design it from scratch today, my design would probably be somewhat similar.