Hufflepuffs in the movie/books always come off (in my opinion) as a teacher's pet always thinking there better, but Slytherins 90% of them at least were either abused or they were taught to bullie and be bullies for ex: Draco, had a soft spot but he had to be mean to be a bully because not only was he taught that way but that was just the only way he could survive in YOU-KNOW-WHOSE army.