ASP.NET MVC is really lights years ahead of other ways of building .NET apps, and is conceptually close to Rails in many ways. (Alas, its backstory is very OSS and un-Microsoft)
The real reason rails generators work so nicely is that most of the components are known. MS pushes entity framework hard, but it isn't included by default. If you don't know what IOC is being used you cannot generate a controller. If you don't know the ORM, you cannot generate a model. Don't even get me started on the fact that most of the community doesn't even use either of those two.