But I'm not sure this argument applies in the 21st century. Languages like Clojure and even Rust get significant attention just for being better, and they are not tied to any must-have tool.
> Languages like Clojure and even Rust get significant attention just for being better
They are not getting any attention beyond Hacker News and reddit. They are extremely marginal programming languages and they both have a very high likeliness to be completely gone and forgotten in the next couple of years.
I wasn't clear - the point is that in the 21st century, you are working in a multi-language paradigm no matter what, tying together disparate services with neutral protocols like HTTP. Nobody knows or cares what language a server is running. So weirder languages are at least worthy of investigation.
EDIT: Also, pg's "Beating the Averages" essay, arguing that non-mainstream language choice can be the foundation of a startup's success, is more or less the foundational text around here.
http://abstractfactory.blogspot.ca/2010/05/how-to-design-pop...
But I'm not sure this argument applies in the 21st century. Languages like Clojure and even Rust get significant attention just for being better, and they are not tied to any must-have tool.