If anyone thinks that the show apologizes for domestic abuse (rather than depicting it and showing an often-realistic scenario of a person who doesn't really try to get out of it, something that still happens all too often today), I would point them to the scene where ...
SPOILER
Carrie tells Julie that she is better off now that Billy is dead, and asks "Am I right?", and Julie says "yes". Having the spouse agree that she is better off now that her husband is dead certainly doesn't imply that domestic abuse is okay - quite the opposite, in fact.