I'd argue that these might be polar examples and that a lot of people (maybe even the majority) fall somewhere in between. I for one cannot imagine being like the Clojure author, committing scratch-pad code into repo. At the same time, I despise the levels of complexity C++, Java and C# have introduced. Ruby and Javascript (and sometimes Python, Bash) are my goto. However, I like to organize things, keep them DRY. A project like Rails is extremely well architected for an interpreted language based on the authors observations. I highly doubt that it is an outlier.