As /u/commiespaceinvader put it in a previous post on the worth of Mein Kampf:

It is my firm opinion that Mein Kampf is not a good historical source for the study of Nazism. "But, just hold on a second, commiespaceinvader", you might say, "isn't an ego document written by the guy who is arguable the person most responsible for Nazism and the Holocaust a pretty great and definitive source?" To which, I would reply, "well yes, it would be if it wasn't all horseshit"

They then proceed to go into further detail about why this is the case in the linked comment.