I answer questions from people new to Ruby a lot (given that I wrote one of the few and the earliest introductory books for Ruby that's free) and they are VERY often the exact questions he mentions here. Maybe people are too lazy to find the answers. Maybe they're utterly immobilized by a new tech stack that has a lot of choices. Maybe they just aren't as smart as you are. Whatever it is, we really need to find a simple way to address these questions. I think a lot of them are already addresses through blog posts, and as you mentioned, through the tutorial you're following, but a lot of them aren't (and sometimes they're answered incorrectly due to the age of the content or simple ignorance on the author's part).
Let's not pretend these people don't exist just because you aren't one of them. Many people do have to deal with this stuff up front due to the nature of the work they plan to do with it, and if the information isn't accessible, they'll just move on to somewhere it is.