I usually love James Hague's posts, but this one has his head buried deep in the sand. And he's enough of a veteran to remember early Lisp and Smalltalk systems, where excessive openness in all aspects looked awesome for prototyping/hacking or academic toy programs (or what is considered toy-size in the last 20 years anyway), but was a disaster even for the mid-1990's definition of programming in the large. Attempts to discipline these languages came too late, so they got overrun by competitors with lots of "paranoid" rules like C++, Java, hell even Eiffel. (Not the single reason of course but one important reason; not even the gurus could help themselves to not abuse dark magic and write application code that would be compatible across minor updates of the language/frameworks, let alone other compilers/VMs/platforms.) If you need extra evidence with more current technology, see most "bad parts" of Javascript (successful, but in the same way that the Titanic was wildly successful for one week; people who build large JS apps have been in a mad rush to fix or replace it for the best part of the last decade, hopefully with ES6 coming as a first major win in that direction).

TLDR sorry James, we have tried the elegance of extremely simple and open language/runtime architectures, and that was always an abject failure.