Do you know the rest of the story, too?
Brooks/Gabriel developed an implementation for stock hardware (typically Unix systems with RISC CPUs: SUN SPARC, IBM POWER, MIPS, PA-RISC) which largely debunked their own earlier critique: Lucid Common Lisp.
See this paper: Design of An Optimizing, Dynamically Retargetable Compiler for
Common Lisp, Rodney A. Brooks (Massachusetts Institute of Technology Lucid, Inc.), David B. Posner, James L. McDonald, Jon L. White Eric Benson, Richard P. Gabriel (Lucid, Inc.), 1986 http://rpgpoet.com/Files/cp.pdf
They even founded a company (Lucid, Inc., 1984), which sold this Lisp very successful for several years. Many companies used it during that time for deployment of Lisp applications.
Richard P Gabriel even co-developed the Common Lisp Object System standard and published the spec in 1988: http://rpgpoet.com/Files/concepts.pdf and http://rpgpoet.com/Files/Functions.pdf
Rodney Brooks also developed a specialized tiny variant of Common Lisp called L, which he then used in many research and commercial robots. 1995
https://www.researchgate.net/publication/2949173_L_--_A_Comm...