Dorothy and the Wizard in Oz

I have been reading the Oz series, most recently the fourth book, Dorothy and the Wizard in Oz (1908). I was excited to read this one again because it's my favorite book in the series.

Or, at least, it was.

Written shortly after the 1906 San Francisco earthquake, the book begins with Dorothy Gale traveling to California to visit family. An earthquake aptly strikes and Dorothy; her second cousin, Zeb; her cat, Eureka; their horse, Jim; and their buggy fall into a crevice. They fall for a while. They then realize that they're not falling as much as floating downward. They land gently on the roof of a glass building deep in the earth, in the Land of the Mangaboos. The inhabitants gather to have a look at their unexpected visitors. Dorothy quickly notices Stepford Wives-like peculiarities: The people are gorgeous, cold and expressionless. "They did not smile nor did they frown, or show either fear or surprise or curiosity or friendliness." There are also no children among them.

A man quickly identified as the prince questions them. When they fell, rocks fell with them, damaging glass buildings. The prince holds Dorothy and her company responsible and wants to take them to see their sorcerer, Gwig. As they speak with Gwig, another earthquake strikes, and another guest floats into town: The Wizard of Oz, in his balloon. He and Gwig battle over who is the more powerful. Gwig eventually uses a Force Choke on the Wizard. But the Wizard pulls a knife from his pocket and gives “a mighty stroke that cut the body of the Sorcerer exactly in two.

"Dorothy screamed and expected to see a terrible sight; but as the two halves of the Sorcerer fell apart on the floor she saw that he had no bones or blood inside of him at all, and that the place where he was cut looked much like a sliced turnip or potato.

"'Why, he's a vegetable!' cried the Wizard, astonished."

Expressionless, the prince has Gwig taken to be planted, so "other sorcerers may grow upon his bush." He then tells Dorothy and her company, in the same emotionless tone, that they are to be executed.

At this point, I am wondering two things: 1.) How was this ever my favorite Oz book, and 2.) How did I ever wonder why more Oz books weren't adapted into films?

I know the answer to the latter: The Wicked Witch of the West had nothing on these veggies. This is the stuff of nightmares.