I love this and think it's very true. Whenever I read a book where I find issues, I always make mental notes. For example, I just reread Catcher and the Rye, and while it's an all-time classic there are some rather weird issues with tone and consistency throughout the book that really stood out to me. Like in the first 15% he says "gives me a bang" a BUNCH but then never says it again... and in the end he says "and all" a bunch, but its never used in the beginning... it sort of feels like two different main characters at times based on the jargon that Holden uses. It's a great book overall, but finding issues in certain works helps to clarify what you do/don't like as both a reader and author.