I don't think there's enough attention on the fact that the strict MVC approach of big old school web frameworks like Rails is an increasingly glaring architectural dead-end. The "model" part of an MVC application is invariably far too complex to crowbar inside a couple of dozen Active Record subclasses. And you can't prescribe a one-size-fits-all architecture for the model from a framework level. That part has to emerge from the business and technical constraints of the specific application in order to be correct.