What I'm referring to is a rhetorical technique deployed to get people to simmer down and accept the status quo. Folks who support Israel know they can't get people to be 100% behind Israel anymore, so the fallback position is "it's complicated, the Palestinians don't seem like great people either so I'm not going to go out of my way to support them". That leaves the ruling class foreign policy establishment to run the horror show the way they like without any troublesome democratic meddling.
If you want to see an example from a historical genocide, just look at what the Turkish government writes about the Armenian genocide.