I'd like to see the real thinking (and data if there is any) behind this decision. Did they do some tests where they asked new users to find and buy a book, and did those users try searching in unity for it?

Or did someone say "How can we get affiliate links into Ubuntu as a source of income?"

He seems to be suggesting this is user led (or at least, aimed at making a better experience for the users). Which I suspect is bullshit, but I could be wrong. I'm not an average user.