You might want to look at a few things too, such as how silly the “everybody did it” argument looks when you apply it to somebody who dropped poison gas on civilians.
As opposed to .303 bullets raking the crowd basically crowded into something the size of a stadium floor until all ammo was expended after about 8 minutes?
The differences are at best, academic.
Also, it is not a defense to say everybody did that. It is more of a pointing out of selective outrage. And when I see that it usually indicates a political objective. If someone is outraged by Italy in Abyssinia, but silent on France and British colonial behavior, that says a lot.
And counterintuitively, during the colonial period, the Germans were the least abusive to their possessions. They were also turning out to be good competitors. This is one of the causes of WWI.