My impression is that Spec Ops fundamentally misunderstands the relationship between player and protagonist in a linear game, and so whatever criticism it tries to make is pointless. The point seems to be that you can't or it makes no sense to enjoy playing out a story that disturbs you. But this can't be a reasonable point. It demands that the player, rather than simply controlling the protagonist's simple actions as the story plays out, takes on the role of the protagonist. How can this be demanded if the player isn't given any story agency?
It is perfectly possible and reasonable for a player to enjoy the gameplay of a game while simultaneously disliking what the protagonist is doing. They don't need to feel anything bad about the actions they take in the gameplay because it just ain't their story. The player is simply playing out the things that the protagonist does. A good example is Arthas in Warcraft 3. His story is quite grim and disturbing, and you're controlling him as he does it, but there's no sense that you should feel disturbed for enjoying the fun of playing an RTS with a disturbing plot.