Let me start this with I genuinely enjoyed this book a lot. One star is only a kind of decency I feel is necessary for the sake of people looking for a way out of this book.
Most people who don't like this book dislike it because it's filled with reused platitudes and overly simple advice. A lot of this book feels like a rehash of what writers are told a million times over. "Stealing like an artist" simply means to look for inspiration from others and this book seems like it was meant as a glorification for this specific author's theft. In my notes on what this book was after I read it, I wrote it off as a sort of manifesto for inspiration. It reminds people what to do if they don't write or haven't been writing.
Coming fresh off a surge of not reading, reading something simple and small like this really helped me personally though, so I did what I always do and go to one star reviews and, unfortunately, noone has torn to shreds a work I really enjoyed. This feels like a real shame to me as I like to see art pieces I enjoy get bashed as it shows there is no real safety for any piece of art. In essence, this is a good work and it has helped me really remember what I started art for, which is not because I wanted to write pretty passages for friends or because I have big emotions, but because it is fun to write, it is fun to be inspired. If you're avidly writing, there is nothing much here for you other than perhaps a few ways to continue you'll find on any buzzfeed article.