^ I agree with the latter half of what you said. Jenny is much more a brat than Karen, and neither is all that bad. And sulking and pouting is not nearly as bad as a temper tantrum. That was one of the points of my post. I was actually defending Karen.
As far as the first half, yes, Ann M. Martin was entitled to write anything Scholastic would publish. But by seriously upping the Karen quotient, it exponentially increased the annoyance many fans felt at Karen's personality. I probably wouldn't have "hated" Karen growing up if I hadn't read the LS books.
I don't recall many times Karen actually faced the consequences of her negative behavior, but if she did, she certainly didn't learn her lesson. She'd repeat the same behavior in a later book.
^ I'm pretty sure that Karen kept repeating mistakes is because they never let her age and there's only so much you can write without things eventually repeating. Some lessons can be learned twice.
Karen tends to get blown out of proportion because she has a lot of attention. Kristy loves her, the BSC likes her, and she has an entire series. She comes off as bratty sometimes here and there but over all she's not that bad. Sometimes in her own series I feel bad for her, like Watson making her own bike that she outgrew like come on.
Most stories about Karen are parodies and a caricature of who Ann was originally trying to write, it's one of the biggest cliches. I'd like to see a story about her where that doesn't happen.