Am I missing something? Why do so many people expect Shattered Space to be fee?

Maybe I’m confused. I understand the rage over the last 6-7 years about the rise of micro transactions, nickel and diming gamers into buying $10 skins, I just don’t see why anyone thinks Shattered Space should be free? I didn’t buy the game, I am using Game Pass which means I don’t own the game. Therefore, I need to also purchase the DLC unless I outright bought the game with the edition that gives the DLC for “free”. What part of this equation am I missing? Is it a bunch of entitled gamers that think we don’t need to pay for content? I’m not even defending Bethesda or any large game studios for that matter, I just don’t ever expect anything for free (some stuff yeah, but not a large DLC like this). No one ever complained about having to purchase any Fallout DLC’s. So, am I not in the loop on something here?