Well, it's not as if he personally went around killing all of them himself. But that isn't the point. In fact, what he did was even worse than him simply going around killing Jewish people with his own hands.
Based on his 50 comments on the "ask funsubstance" post (from a year ago), its mgoveia's job to control funsubstance. Why don't you make you're own my stupid pony site?
I don't think anyone said that it was rascist... but what Hitler did was horrendous, and that's what the post is saying - even just raising your arm wrong will get people having a go at you (different guest)
That's guests' job.