They don’t want you to watch obscure shows, they want you to watch the top ones (in your region!) as they are preloaded into your cdn already.
User viewing preferences seem to be a secondary consideration.
I wonder about that too. Of course, the Netflix in-house productions will be getting extra promotion; but setting those aside, I fail to understand why Netflix promotes (e.g.) romcoms to me; I don't watch romcoms. I've never given Netflix any signal that I favour romcoms.
I can only suppose that some motivation other than giving subscribers what they want must be at the root of it.