That's obvious nonsense. Eternum, Cosy Cafe and Pale Carnations are examples of HS games that are thriving and seem to be in no danger of being abandoned. Once in a Lifetime (Eternum's predecessor), AlwaysFan (similar to Pale Carnations), Now & Then (road movie during zombie apocalypse), Solvalley School (sitcom) and My Bully is my Lover (harem with romantic couple story) are examples of large finished HS games. (Solvalley School and My Bully is my Lover have proper endings. They are just not officially finished yet as the developer wants the option to add additional endings.)
These are some of the best and longest of all Ren'Py AVNs. In terms of quality, Stormside fits precisely into this list. However, the developer made it clear from the beginning that he isn't motivated by money but by an artistic vision that involves immense branching and was always likely to lead to slow development. Maybe the negative feedback from people who were not prepared to accept that combined with time constraints and the practical difficulties of branching ate too much motivation. I hope there will be a miracle and the developer turns up again to continue the game anyway. It would be a shame if not, though of course what we already have is extremely valuable anyway. Stormside will always be one of my favorite games, even if the current version is all we will ever get.