So Hitler is believed by many people to have a Jewish grandparent
He might have eventually had to admit that his own relatives were ruining things for other people
And that ruining things for other people made things worse for Jews in the long run and thus worse for him
He might have realised Jews might not survive if they both depend on Germans and destroy the Germans they depend on at the same time
Then he tried to train them to work and not be parasites & tried to kick them out