That section was for people who were using camera phones with on screen touch focusing (the iPhone camera app also adjusts the exposure for the area where focus was selected). The section on dSLR spot focusing was to explain how to do that with dSLR's if you wanted to.
The next chapter on frame exposure settings goes over using exposure compensation.
Your only valid criticism is that the Aperture chapter's photo is poorly exposed.
There's one good photo in the whole book, and that was taken with a p&s (s90) - something you claim cannot resolve more than 15' in front if the lens and takes a second to shoot. Both point are of course are completely wrong and misleading.
The 'book' (quoted because its really just a few dozen paragraphs) looses any credibility when it's accompanied by photos that are so awfully made.
I don't disagree with you on how those particular photos are blown out, but those were candid shots in irregular lighting. To make a conventional shot, you would set up lights and possibly do significant post processing. I chose to emphasize as much of the area that I wanted even as details are lost at the other end.
The main point of the book is that there are options in the first place and it's important to be aware of them to properly adjust...rather than just snapping a photo and wondering why it turned out so off.
It's difficult for me to show what the choices were, granted, because I didn't shoot those scenes with thhe intention of demonstrating a decision tree for the final shot. Being able to show more direct comparisons, between the exposure options, is my intention as I add new examples to the book
As far as the metering section, I think you're right that it's confusing...I decided to split off the chapter with doing touchscreen exposure and never fully fleshed out standard metering. That is something I'll work on