Newbie question. Can anyone explain why people would want to override the standard dispatcher? E.g. in
http://www.lispcast.com/files/episode3/reddit-lisp.lisp

(defclass handler ()
  ((url
    :initarg :url
    :accessor url
    :type string)
   (handler
    :initarg :handler
    :accessor handler)
   (name
    :initarg :name
    :accessor name

    :type symbol)))

(defvar *handlers* (make-hash-table))

(defun our-handler (request)
  (let ((handler (gethandler (hunchentoot:script-name request))))
    (when handler (handler handler))))

(setf hunchentoot:*dispatch-table* (list 'our-handler))