Well, you know, we all want to change the world!
The point to Cat which makes it so annoying as a casual-read novel and IMO so important in Heinlein’s canon is that it defines from the very title what it is attempting to do, and then we get annoyed when it actually does it.
We want our fiction carefully wrapped, with no loose ends (unless they’re set up for a sequel). Real life isn’t like that.
Worse, according to modern indeterminacy theory, the fricken Universe isn’t like that, with things that are not only not known but unknowable. Indeterminacy, quantum theory, collapsing of quantum indeterminacy.
“Pixel is Schrodinger’s cat.” Somebody (Jane Libby?) says that explicitly in the book. Is Schrodinger’s cat alive or dead? Under the setup of the thought experiment, you can’t know – until you open the box after the experiment. And that is exactly where Heinlein leaves Pixel – and the protagonists.
What about all those loose ends? From Enrico Schulz to Bill the Galactic Derelict to Rabbi Ben Ezra? (and yes, the puns are intentional, and not, I suspect, mine but RAH’s) Heinlein makes a half-baked attempt at explaining some of them via Uncle Jock and Jubal, but intentionally leaves several unexplained.
Just like real life.
Back in Number of the Beast, there’s a discussion between the four lead characters on the distinction between “random” and “chance” and whether anything is “pure chance” that still leaves me sleepless occasionally.
Heinlein’s creed was that all problems have solutions.
Quantum theory and indeterminacy, along with Godel, say that not only do not all problems have solutions, but we cannot possibly know the answers even if they do.
To a man of Heinlein’s makeup, this abdication of scientific inquiry into a sort of vague mysticism was unconscionable.
So he devoted an entire book to saying, It won’t work; it isn’t true. There is an answer. Here’s why it’s so much BS.
If the book leaves you vastly unsatisfied, that’s precisely his point. As Jake Burroughs says, in so many words, in that discussion in the Dora that Lazarus’s bad temper (where’d he get that from?) ends.