Lisp is unpopular.
Yes, you won't find Lisp language on the top of the charts kind of "the most popular language worldwide". But, firstly, 'ad populum' arguments are even irrelevant. Secondly, pure Lisp is something ancestral and is rarely used directly today.
Lisp 'reincarnated' into dialects and blesses other languages with its concepts and ideas, including:
- higher-order functions
- dynamic typing
- tree data structures
- prefix notation
- garbage collection
- exception handling
Lisps have powered multiple platforms across different industries from e-commerce to data mining and modeling & simulation. It has been successfully adopted by multiple commercial vendors. Roomba vacuuming robot, Mirai that was used to model the Gollum character for the LOTR movies, Arrival's service platform (a British electric vehicle developer) — we can extend this list but better read about it in our previous blog article.
Lone wolf developers and scratch-an-itch model.
A lot of things in Lisp programming are up for grabs. Often it results in multiple competing implementations of lazy evaluation, type inferencing, arrows, pattern matching, etc. 'Because you can be so powerful alone, you work longer alone'.
Nothing criminal but it provokes some negative tendencies of individualism, such as reinventing wheels, throw-away design, and lack of documentation. Individual programmers often don't handle related parts of the problem which would make the program more useful to others. A solution to the problem is making collaboration 'easier than individualism (for people who care about thought and beauty)'.