Before Bella became pregnant, I think Jacob was the only one that was angry about her becoming a vampire. I think Sam wanted to let it go since she was making her own choice. Sam wanted to attack once he learned that Bella was pregnant. Once Jacob found out that Bella was still human, he sought to protect her and her "demon baby". Once Jacob imprinted on Renesmee, everyone simmered down.
So, to recap:
Vampire Bella, no baby--Jake attack
Human Bella with baby--Sam attack
Human Bella, no baby--Twilight-->Eclipse
Vampire Bella with imprinted baby--one big happy family.
As far as that being "the only good thing about Renesmee"...i think that people are overly harsh on Renesmee. In the book, everyone loves her...how is it that so many people outside the book think she is awful? Her character does nothing bad...in fact she just makes everyone happy (except for maybe Leah).