LISP users prove they can be as arrogant as many believe them to be. All things considered, much of the thread was pretty revolting. One poster offered the following "solution" to a new LISP programmer.
(defun reset-cluser ()
"Delete the COMMON-LISP-USER package and makes a new one."
(let ((setp (eq *package* (find-package "COMMON-LISP-USER"))))
(let ((*package* (find-package "COMMON-LISP")))
(mapcar (lambda (x) (ignore-errors (delete-file x)))
(when setp (setf *package* (find-package "COMMON-LISP-USER"))))))
Fortunately, most of the LISP folk I've met are pretty nice folk, but that was pretty awful.