The Shape of Code

While many developers have a favorite programming language, there are a few who believe they have found the One True Language and refuse to even consider coding in another language.

Why is the One True Language invariably a dialect of Lisp or a functional language?

I think the reason is the same as why strict churches are strong, both these language families make life difficult for free riders, i.e., the casual programmer.

Superficially Lisp-like languages look unwelcoming because of all those brackets and the tiresome reverse polish notation, but once past these surface speed bumps life is not a bed of roses, there are mind bending language challenges to master at every abstraction level; developers get sucked into the community working on mastering each level (this suggests an alternative explanation that coding in Lisp is a way of continuing to play Dungeons & Dragons while appearing to work).
True functional languages don’t have global variables and certainly don’t let you create stateful information. The self-flagulation no global variable languages have a limited clientèle; its the writing of programs that don’t make use of side-effects (e.g., iteration via recursion, not explicit loops) that marks out the true community members; a short conversation with a developer is enough to tell whether they are one-of-us who joyfully tells the world of their latest assignment-free solution to an apparently intractable problem (intractable in the sense of appearing to require the use of assignment statements). There are always umpteen different ways of writing something in functional languages, providing plenty of scope for sects to splinter off by requiring disciples to follow a particular approved style.

Why have Lisp and functional programming continued to survive for so long? Some interesting research on communal societies has found a correlation between the number of costly requirements entailed by community membership and community longevity, the greater the number of costly requirements the longer a community survives. Having sunk so much time and effort into the costly signaling required for community membership, people are loath to leave it all behind.