To answer your question from the other thread...I think that one reason that Cat gets debated so much and Sandor, Gregor, Randyl Tarly, Tywin Lannister, Roose Bolton and Ramsay (Snow) Bolton, among others, don't get debated, is because they do not have PoV's.
If I may jump in here...
I agree with the lack of POV theory, but would also add that none of the above examples are considered the caretaker parent of young children...either the children are full grown, or altogether absent. Lacking both POV and young children replaces/eliminates the ambiguities and stereotypes that are very often applied when in judgement of Catelyn. I'm not screaming sexism here, but simply pointing out that if Catelyn were unmarried, childless, and related to the reader through another character's POV, she would be 1) less interesting in human complexities, and 2) relegated to a tertiary character who is easily boxed in as either good or bad.
I never considered Cersei and Jaime anything but monsters until I had to start internalizing their thoughts. For me, and I know I am a little judgemental, both will always be seen through the prism of Bran. Whatever redemption and growth GRRM gives us for those two in the future, Bran will always be on the scales weighing against that.
I agree on the Bran scale, but disagree with Cercei achieving redemption through a POV. She has, and always will be a monster to me of the basest sort. Jaime? I believe, when all is said and done, that Jaime's POV will serve most in exposing just how toxic an influence his sister is. Redemption? Of the two, he's more likely to achieve it, but I'm not betting the farm on it. YMMV.
Also, while I'm at it, that Catelyn "had no other choice" is a fact if we recognize the inherent plot device in play, and agree with Jon's much debated parentage. Her being a kind and loving mother to Jon would have drawn far too much attention from the petty, gossip mill in KL, which would inevitably led to charges of treason, and punishment thereafter. It's convenient, tidy, and excuses everyone from their actions.
I don't agree, but that's an entirely different kettle of panties.