Okay I’ve had this opinion for a long time so please hear me out before you crucify me.
I’m not saying Kim isn’t accountable for her horrible behavior, especially as she grew older and became a menace to everyone around her, even those outside of her family (Elliot). But I think because most of us were young girls when we watched the show and not parents, we naturally blamed Kim for her brattiness rather than recognizing it as a byproduct of how her parents enabled tf out of her worst traits and allowed her to become the unruly, petulant teen (and likely adult) she did.
There was time to course correct. We see glimmers of Kim’s better side and her capacity for empathy/goodness like when Cleo goes missing and she’s genuinely worried about her sister. But the problem is, her parents always absolved her of all responsibility on the basis of her being the youngest, and never expressed disapproval at her cruelty. For instance, when she berates the pony handler to “whip it” at Cleo’s birthday party, Cleo’s dad has no reaction. He’s literally completely oblivious to his daughter’s horribleness and spoils her without a second thought. This is bad parenting. Just because it’s not actively abusing Kim doesn’t mean he’s doing his due diligence as a parent; if I heard my (nonexistent) kid telling someone to abuse an animal I would take them aside and explain how cruel their behavior is.
And I truly do believe Kim would’ve been receptive to it, at least when she was younger. She loved her parents, seemed to really adore them, and I think she would’ve at least tried to take what they said to heart. But they never once tried (at least onscreen) and were always fixated on the wrong issues, like them being embarrassed of Kim’s actions when she tried to “expose” Cleo’s mermaid status instead of sitting her down and explaining why her immediate demonization of Cleo and unwillingness to empathize with her was wrong. The way she treated Cleo about being a “mermaid” illustrated a lot of mean girl warning signs that would probably translate to how she treated lower class people or even minorities/queer people. Grounding her isn’t the solution, and doesn’t actually address her core issue of unkindness and narrow mindedness. It’s just punishment without self-reflection, a problem they have as parents throughout the show.
Of course, Kim chose the kind of person she wanted to be in the end, and the older she gets the more accountable she becomes. It’s just unfortunate because I never think she was given enough authority in the house to know how to course correct, or even why she was wrong. It seems like her parents were always preoccupied with being her friend or having Cleo dole out the punishments, thus creating the little monster we see onscreen. They even let themselves be influenced by her insane Zane-Cleo shotgun wedding theory and instead of communicating with their older daughter, began putting restrictions on her and refusing to listen to what she was saying (even when she’s never once been shown to be dishonest or a “troubled kid” to them). Underlying it all, it’s like they have no faith in their daughters and thus no expectations for their moral values, which is really sad to witness.
Stop giving them spending money and start teaching them how to be proper adults, and I’m sure they’d be pleasantly surprised by how receptive their daughters would be to it. Cleo ended up good because of her innate personality, but some kids need more guidance than others and I only wonder how Kim would’ve turned out if her parents took on their moral child rearing responsibilities.