Developer productivity is important - Reality or Myth?

Today i was reading a post by Rob Conery in which he discussed both his thoughts on developer productivity in relation to the creation of a new OS project (ASP MVP), and how he may have thought that in some instances hiding behind WebForms and not touching MVC was really just laziness or ignorance mistaken for productivity. Additionally i also read another post by Scott Bellware in which talks about a similar subject, in that developer productivity when viewed in isolation, is really a myth.