I mean IOF are psychos, but that's an APFSDS shell. It's a big tungsten dart with no explosives in it. The only thing it can really destroy is an armored vehicle, since if you shot it at a car or a building it would just punch straight through and make a little hole.

So in context, this just seems like a really tasteless joke about "innocent tank crews". It's hard to find any extra outrage for this specifically.