Because Dunc 2 was where most of the changes from the book occurred and the plot suffered for it
Chani isn’t supposed to be this emotional, unsupporting bitch to Paul, she is just as fanatical as anyone else
Alia is supposed to be born and a child already, not just in Jessica’s womb and in Paul’s dreams
There isn’t supposed to be tension when Paul says he’ll marry Irulan. Chani knows he loves her and that she has to be the concubine for political reasons, and Paul explicitly states he will never love Irulan or have children with her and the marriage is purely for political convenience.
Also you see way more of Zendaya who is a horrible actor and needs to be in way less things
DUNC part 1: certified fresh™ kino
DUNC part 2: gay and retarded