The author Vimalathitha Mamallan says you have to be true to yourself if you want to write a piece of literature worth reading. If you are unsure about something, it will show up in your writing. The writing should have lived experience and pass it on to the reader's heart.
He dissects bad pieces of writing (mostly short stories but also blog posts, prefaces etc) and uses the occasion to share his thoughts on writing. One exception is Vannanilavan's Esther, which is among the most noteworthy stories written in Tamil. (It is included in the book). Mamallan praises it lavishly but doesn't attempt a detailed review. In a way, this book is the opposite of the author's earlier offering Punaivennum Puthir, a best seller. It showcased the intricate beauties of some of the finest stories. OTOH Ezhuthukkalai exposes the not so finest ones-- detailing why Mamallan can't care less for them. It is another matter some of them were big hits with the fans of the respective authors when they were published ;-)
And no, it's not a book meant to teach you how to become an author. In fact VM actually says it's perfectly okay if you can't even read serious literature, let alone writing any; there might be a hundred other things you are good at. So read this book and spare the reader : -)