I finally figured out what it was about IKSW that I didn't make a whole big splash about it unlike Casey's other two books. It's about the good, the bad and the ugly.
Shara had a secret. And to protect that secret she took an ugly, compicated, overcompensating road. Chloe wanted to define herself so went down with the 'Bad Bitch Deal With It'™ persona route. Smith figured out the clues about halfway through but kept silent. Most of the characters in IKSW do bad things, and as teenagers living in a stressful controlling environment, while it may not be justified, the source of their choices can absolutely be understood.
And that's something that's been missing in RWRB and OLS. Alex and Henry never do anything outright morally wrong. The OLS gang, as chaotic as they are, commit multiple felonies but not a moral wrong. Maybe they're grownups, maybe their circumstances are different, maybe Casey has progressed with their writing style. Either way, this is a new thing to have been introduced in the Mcquistonverse.
And let's face it, none of us likes having the ugly side of us being pointed out. And as brilliant an author Casey is, they've pointed something out to each of us that resonated, and those things are not necessarily sunshine and rainbows. Which means, we've put it away, let it wash over and forgotten about it. Because of course I'd rather read about Henry playing piano to Alex or Niko being a psychic plant dad than realize how angry and hurt and raging I've been as a teenager, and how much of that stemmed from the lack of emotional support from the people who were supposed to be it