Interactivity = agency. What I mean by this is that because the medium is more interactive than most others, the developer/end user expects to have agency in the world they inhabit. The user should make a difference. Rather than reading about WW2, the user should be able to fire the weapon. This is the most difficult problem to solve. Everyone wants to be a hero in their own story.
Again, I think the main problem isn't an overabundance of games geared towards violence, but that it is too financially prohibitive to produce something else. Settlers of Catan continues to sell, yet a game will be old news within months of release, due to how games are produced and marketed.