Basically...his arguments are as someone saying the Earth is flat, refusing to listen to the evidence otherwise, claiming no one has any proof because he can't tell with his own two eyes. Him never debating, only claiming no one else was willing too, only cements this further, and that rational discussion is a lost cause (as we've seen)
And yes, there are many similarities between what the Garleans are doing and the Nazis did in WW2. Heck, the Garleans are even based on their "perfect" race...
I also find it very ironic that I'm one of the people that thinks Gauis is still alive and we'll be allying with him in 4.0. Weird huh?