I hate that it's called "holocaust denial", as in abject denial that anything happened. Yes, the Germans rounded up dissidents like literally every fucking other country in WW2. Yes, wartime conditions became abhorrent as things progressed and even regular German citizens were starving in the streets towards the end. Yes, Jews and a bunch of other Europeans died in concentration camps.
But come on, "mass murder"? Gas chambers? These were soldiers, not fucking cartoon supervillains.