In Simon vs. the Homo-Sapiens Agenda, the only thing worse than the title was the character of Leah. Leah got angry at Simon for no reason on more than one occasion, and her motivations were entirely shadowy from start to finish. She was the least defined of the entire Simon crew and the least worthy of the reader’s attention. Leah existed to make Simon feel bad, and he had enough to feel bad about in the first place.
A book is the crystallisation of a moment in time. To add anything to that runs the risk of disturbing the balance of the original story. In Leah on the Offbeat, Becky Albertalli, answering the call of “the readers who knew something was up, even when I didn’t”, has written a novel solely to pander to fans of an obscure “ship”. The balance has been disturbed.