I know people who work in the embedded space working on stuff similar to traffic lights and LISP isnt even on their radar. Rust is. LISP isnt.
Every niche language has its fanboys who can end up using it all over the place but when it doesnt spread to non fanboys there is usually a reason to which they are wilfully blind, usually related to its practical value.
Lisp is not a really a programming language. It is an idea.
Lisp didn't emerge the way most languages do - someone sitting down to design syntax and features for practical software engineering. McCarthy was formalizing a notation for computation itself, building on Church's lambda calculus. The fact that it turned out to be implementable was almost a surprise.
And that origin story matters because it explains why Lisp keeps regenerating. Most languages are artifacts - they're designed, they peak, they fossilize. Lisp is more like a principle that keeps getting re-instantiated: Common Lisp, Scheme, Racket, Clojure, Fennel, Jank. Each one is radically different in philosophy and pragmatics, yet they all share something that isn't really about parentheses - it's about code-as-data, minimal syntax hiding maximal abstraction, and the programmer's ability to reshape the language to match the problem rather than the reverse.
The counterargument, of course, is that at some point the idea has to become concrete to be useful, and once it does, it's subject to all the same engineering tradeoffs as any other language. Rich Hickey for example made very specific, opinionated decisions that are engineering choices, not mathematical inevitabilities. So there's a productive tension between Lisp-as-idea and any particular Lisp-as-language.
> related to its practical value.
Don't be daft, preaching pragmatics to modern Lispers is like trying to explain synaptic connections and their plasticity to neurosurgeons. They already know what's what - tis you who's clueless.
At no point does a post about "You can't draw sweeping conclusions about this kind of thing" imply "all dark matter tech relies on esoteric stacks". I'm not sure why you would even bring up that anecdote?
> there is usually a reason to which they are willfully blind, usually related to its practical value.
Lame passive aggression aside, I'm not a Lisp "fanboy" and I actively don't like the grain of the language. Language adoption is always down to familiarity, taste and ecosystem constraints. But I'm also not deluded enough to assert something like this because I actually know better. It's an argument that's always positioned without substance, because there can be none. You're positioning ignorant snobbishness as enlightened pragmatism, no offense but that's just pretense. If you can't get a Lisp program working on a 100mhz microcontroller with 5k of flash, that's kind of a skill issue dude.