Did he say that people will understand everything Hitler did? If he said that, I could understand the objections. But it sounds as though he just said that Hitler was insane, which sounds reasonable enough to me. Maybe he does identify with Hitler, as you suggest, but I could find nothing to confirm this on the web.
Prime Minister Netanyahu's meeting with security chiefs ends after four hours (haaretz)
from the article: Kanye enrages fans by identifying with Hitler