dhh has spent so much of his career actively leading Rails that it's tough to tell the difference between his personal evolution as a developer and general trends in the industry. I don't think he even attempts to make a distinction in this essay.

I worry about a push away from unit tests. I can't imagine having to refactor a large application with only system-level integration tests to work with, especially in a dynamically-typed language like Ruby. I haven't written a Rails app in a long time though, maybe these days it's easier to just start over than to refactor.

But any bad day for dogma is a good day for the rest of us. Write software using whatever methodology works for you and always question the value of so-called "best-practices".