I completely agree. The wording is so basic and kind of insulting as seen here for instance, "Text fields allow the user to type text into your app. They can be either single line or multi-line." Very elementary for either a developer or a designer to read.

If the goal is to bring devs in from other platforms, who might have all kinds of crazy notions about what Android dev entails, erring on the side of over-simplification will give more people the sense that "hey yeah, not so hard."

Isn't it for Designers, rather than Developers?

Designers, managers, or any other project stakeholders. Many of whom may have the same understanding as customers.

I think it might be too early to pass judgement. I would hope that over time Google releases sample applications, better widgets, and so on to take care of the boilerplate. (Similar to HTML "grab and go" type sites.)