I'm aware it's probably not intentional, but you describe Scala as being eclectic, and then immediately criticize Scala For The Impatient for presenting it as eclectic!
However, I do feel like you're right. For instance, the section on XML literals probably should have been avoided, since that feature doesn't fit nicely with the rest of the language and most of the time isn't necessary to know.
I think that's totally consistent. It's bad that Scala is so eclectic. It's also bad that introductory books present Scala as eclectic instead of selecting the "best" subset of Scala to teach.
However, I do feel like you're right. For instance, the section on XML literals probably should have been avoided, since that feature doesn't fit nicely with the rest of the language and most of the time isn't necessary to know.