It would be sadly missing the mark to summarise
McCarthy's influence by
looking at the popularity of certain Lisp-based languages. In reality
his influence pervades and transforms almost everything we do.
In this way he stands with greats like Alan Turing and
the late Dennis
Ritchie.
(And Lisp's insights are, if anything, *gaining*
importance. Functional
programming is the future, not the past.)
Leaving aside LISP and its descendants, JMC would still be important in the
history of computing for having first named and described the concept of
"timesharing" in computers. (NB: Strachey's concept of
"timesharing" is
rather what we now call "multiprogramming" or "multiforking", as he
himself
said to McCarthy decades ago.)
If not for timesharing, DEC would not have created the PDP-6 which begat
the PDP-10 which hosted or inspired a large number of developments which led
to the world of today.
Rich
(laptop, Germany, no .sig)