It's a little hard to articulate, but SoM doesn't really put much design or gameplay emphasis on "place." There's not really much reward for exploration and, in my opinion, Mordor doesn't feel tremendously like a real, lived-in locale. It's the area the game has the most room for improvement, for sure.
I don't mean this lack of "place" as additional criticism, though. I actually mean the opposite. You're so focused on killing orcs and gaining intel and slotting runes and just generally being a badass that I didn't even really consider that there's no mountains or forests. It just.... isn't what this game is, if that makes sense. It doesn't draw attention to location.