Ughh... there's just something so poisonous about an atrocity denial.
Firstly it accuses that group of people of creating a tremendous false accusation
Secondly, it tries removing sympathy from that group (so they can be freely hated)
Thirdly it tries to deny the evils racism/ideology is capable of.
Me, I think these people aren't just 'logically wrong', but 'morally wrong'. Wilfully twisting the truth to justify descending into the nastier, more primitive parts of their own brain - and then spreading more hate.
Although there's also the issue of upbringing by racist family, and their associates...