That's because Nazi sympathizers and white supremacists are naturally drawn towards WW2 fantasies where Germany is portrayed sympathetically or treated like they had a chance of winning.
Can't say any time I ever chose Ostheer in my 600+ games of them in CoH2 that I was ever on a power fantasy about the Nazis ruling the world. Instead, I simply enjoy the design of the faction the most (the need for combined arms to win, the feeling when you bring a fresh tiger tank on the field, et al.) Similarly, when I play Germany in games like Hearts of Iron, it is because it is funner to be the aggressor than it is to sit around and wait for things to happen.
You could argue that this is just me, but somehow I find it doubtful that every Ostheer player other than me is some kind of undercover racist. No idea why your inclination is to simply say people who enjoy playing Germany must be as you stated, it is odd to immediately try and paint a collection of people in such a light.