That first (and, to the extent that the author relates the two, second) point feels pretty dubious. I imagine most adherents of the "directory by feature" camp come from the Django-like world, while "directory by type" campers have Rails-like backgrounds. I haven't found a concrete, objective reason to use one over the other. I tend to find a hybrid, "directory by feature" organization mirrored in each of the MVC roles to be the best of both: easy to find all views or models at once and therefore easy to spot and combine functionality across similar models or views, but also easy to find all files related to a feature via grep/fuzzy searches/navigating through the same directory names from different starting points.