I didn't get that out of his story. There's an issue of semantics, maybe? His argument isn't that the dictatorships followed socialist policy but that they said they did. Hitler didn't call himself a dictator, though he certainly was one. I again want to point to his words, "called itself socialist". And it did have what looked like "socialist" programs, for example, nationalizing companies for the war effort. Programs to breed more Aryans. Programs to euthanize people who brought society down (abhorrent, but was sold through socialist propaganda).
I didn't read that the author was saying that "leftists are self hating people with a need for power". What I read, and believe, is that those with a need for power use socialist propaganda (promises, don't deliver) to gain political control. I believe, in the end, you and he have the same views of what's good and bad.
Germany's government today is in NO WAY a similar socialist government to the Nazis. Did he says that? Do you disagree that Hitler rose to power on a wave of socialist promises? Again, not socialist in the real sense, but in a sense too many people couldn't tell the difference from the real thing.
That seems to be a constant threat, more so these days. Maybe read his story again but try to allow that you're both tackling the issue from different perspectives?
There were many people at the time who knew EXACTLY where Hitler was going. Calling him evil didn't stop it. Trying to reason with people didn't stop it. Why?