(Playing devils advocate)
If we're into banning squads that committed unreasonable war actions, do we start banning Allied bomber squads that carpet bombed CITIES that targeted people directly with incendiaries? This included the targeting of civilians of Tokyo and Dresden. In war, we often cannot say what is right and wrong because we always look through rose coloured lenses. Had the Allies lost the war, I'm sure history would paint us as evil doers too, especially the commanders and squadrons that partook in some of our own questionable tactics. But we won. Dresden was a murder of over 40,000 civilians, Tokyo over 100,000. But this is different.
The difference is the nature of the SS - they were uncharacteristically brutal hence our knee-jerk reaction to the Waffen SS squad. It was a known evil assassin squad in WWII. To recreate it now is accepting them into our gaming family. That is not acceptable.