I like the idea of it targeting developers but aren't most developers going to end up using an ORM in the end? For example SQLALchemy in Python and ActiveRecord in Rails. Is the book a ton of SQL examples or general theory? Most of my day to day database activities as a web developer are creating good indexes, data modeling and setting up queries with an ORM.
I spent years in all sorts of ORMs and have sworn off them in favor of pure-SQL patterns like yesql (for Clojure) and massive-js (for Node.js). For me, the boilerplate of writing SQL queries is trivial compared to the productivity and performance inefficiencies of trying to understand and work around the magic of ORMs. Writing pure queries also encourages good practices like writing field lists in your SELECT statements and using more of Postgres' built-in functions.