There are varying degrees of repetitiveness, however. Although it's a pretty good game, I would agree that a valid knock of SoM is that it does feel overly repetitive because the enemies you fight are largely the same though the entire game (orcs). Plus there isn't much variation on how you fight the orcs or how they fight you.
Contrast with a game like Bloodborne, where, yeah, on an abstract level you are repeating the same actions over and over again (fighting monsters), but the approach you take for each monster has more variety than SoM and you are constantly running into new monsters that require new tactics as you progress through the game.
Of course, compare SoM to a game like Dynasty Warriors, and it's less repetitive in comparison. It's a spectrum.