You have to at least understand and put yourself in their shoes though. They're so xenophobic and "rotten" sometimes because they've been through hell. Azura transforms all of them physically, while at the same time their existing gods are cast down and replaced with an almost Nazi regime type pantheon of "fake" gods. It messes with time like crazy, so they're brainwashed by it's non-linearity into thinking that the Tribunal were true from the beginning and has always existed. On top of that, rumors of Nerevarine and then after with Baar Dau, when Vivec upped and disappeared altogether abandoning his people even though he could have CHIM....it's kinda like how much can one race go through in such a short span and still survive? They barely are.
They have not been through hell, and if they have, it is entirely their own damn fault. The Dunmer were originally Aldmer, then branched off into the sect of Chimer. They abandoned their ancestral ways to follow the three "Good Daedra," Azura, Boethiah, and Mephala. Azura, who manipulates mortals to her own selfish jealous prom-queen desires. Boethiah, who is all about deceit and conspiracy and constant fighting. And Mephala, who might just be more manipulative than Azura, and spins her webs in the name of murder and assassination. And they called these the "Good" Daedra.
Their transformation into Dunmer might not have been Azura herself, but it's so often credited to her that we'll say it was her. However, almost immediately after, Sotha Sil stepped up and gave a big speech about how awesome the transformation was and how it made them unique and it was a good thing. Their pantheon was also not "cast down," but the three Good Daedra were merely made into the Anticipations of the new pantheon of the Tribunal. They still revered these gods, they just had new gods that were by no means "fake," but even more
real than any Aedra or Daedra, as these gods were once mortal, they were once
like them. And while the Tribunal did rewrite time and make it so they had always been gods, this hardly counts as "brainwashing." The Dunmer knew damn well the Tribunal had not always been gods. It's stated and documented in several books available at ease throughout Morrowind. I'm also not sure if you're using the "Nazi" term in comparison to the Tribunal, but if so, nothing could be more wrong. While Sotha Sil and Almalexia had their problems once Dagoth Ur got Sunder and Keening and kept them away from the Heart of Lorkhan, before that, they were nothing but benevolent and helpful to the Dunmer people, and, along with Vivec, preached love and companionship.
This hardly sounds like going through hell by any stretch of the imagination. I can't see anything but a group of rotten Aldmer who decided they were too good for the other Aldmeri. If you'd make them be a victim, then the assailant is themselves. A better question is how much can one race go through before they decide to change their ways?