Other programming languages, while claiming to be simpler, require programmers to reinvent in a haphazard way a significant amount of needed functionality that is present in Lisp as a standard, time-proven base.
It can also be interpreted as a satiric critique of systems that include complex, highly configurable sub-systems.
Paul Graham also highlights the satiric nature of the concept, albeit based on real issues: That sounds like a joke, but it happens so often to varying degrees in large programming projects that there is a name for the phenomenon, Greenspun’s Tenth Rule.
[5]Hacker Robert Morris later declared a corollary, which clarifies the set of "sufficiently complicated" programs to which the rule applies: …including Common Lisp.
[6]This corollary jokingly refers to the fact that many Common Lisp implementations (especially those available in the early 1990s) depend upon a low-level core of compiled C, which sidesteps the issue of bootstrapping but may itself be somewhat variable in quality, at least compared to a cleanly self-hosting Common Lisp.