> RMS's dislike of Common Lisp really caused a colossal amount of damage. Imagine an Emacs written in Common Lisp instead of Emacs Lisp, with decades and decades of improvements.
If Emacs were written in Common Lisp, only people on big mainframes would have been able to use it in 1985, and it probably wouldn't have become popular in the first place. Also, implementing Common Lisp would have taken much longer. RMS has said that his main goal with his LISP dialect was to keep the programming language as small and performant as possible, since at that time, machines had maybe 1MB of RAM (if you were lucky) and no virtual memory. This is why for instance he decided against lexical scoping (and still, Emacs was known back then as "eight megabytes and constantly swapping").
If Emacs were written in Common Lisp, only people on big mainframes would have been able to use it in 1985, and it probably wouldn't have become popular in the first place. Also, implementing Common Lisp would have taken much longer. RMS has said that his main goal with his LISP dialect was to keep the programming language as small and performant as possible, since at that time, machines had maybe 1MB of RAM (if you were lucky) and no virtual memory. This is why for instance he decided against lexical scoping (and still, Emacs was known back then as "eight megabytes and constantly swapping").