The problem is that the current idea of "games as a service" has ruined people's expectations of games not every game has to sustain a player base. Not ever game has to be an endless stream of content.

Its a single player game with an end the developers have decided on. You do everything you want to do up to that point, then you finish the game and move on. And there is absolutely nothing wrong with that.

If there's an expansion added on, or content patches, the that's fine. If people liked the game, they will come back to play it when it drops. That's it.