I'm not certain that shooting is a core mechanic in a strict majority of video games (may also depend on how you define shooting, is flinging fireballs around shooting?).

But aside from that, Campster argued in his video about violence in games (<https://youtu.be/wSBn77_h_6Q>) that violence is easier to program in an accessible way than nonviolence.

Nonviolence requires more understanding than violence.