I think that's more attributable to the fact that for most people, their first 10 hours with Lisp are spent writing recursive functions that explicitly cdr down lists, rather than the names car and cdr. I think it would make a much bigger difference if more people's first exposure to Lisp was something like:

    (with-open-file (input "foo.txt")
      (loop for line = (read-line input nil)
            while line
            do (write-line line)))

But instead most schools only use Lisp as a vehicle for teaching the basics of recursion and functional programming, rather than as an immediately useful tool, so most students go away with the idea that that's what Lisp is used for, and attribute their difficulty understanding The Little Schemer to difficulty understanding Lisp.