Why is Lisp Hard to Read?

With Lisp, you give up on visual cues, such as [], dot-for-member, and others. On the other hand, what you gain is far more valuable: being able to extend the language in a uniform and consistent manner, i.e. macros.

I think the best example is when Python in 2.5 added the with keyword and associated protocol changes to classes (__enter__, __leave__), e.g.:

with open("foo") as f:
  do_stuff(f)

Of course, to support this, changes had to be made all over the Python implementation, whereas in Lisp, you would just define a variation on the WITH- theme...:

;;; note: w-o-f is already defined in Common Lisp!
(defmacro with-open-file2 ((stream path) &rest body)
  `(let ((,stream (open ,path)))
     ,@body
     (close ,stream))

;;; Example usage: write to a file.
(with-open-file2 (f "foo")
  (format f "Hello, World!"))

To better understand the line noise going on in the macro, let's expand the macro:

(macroexpand-1
'(with-open-file2 (f "foo")
  (format f "Hello, World!")))

... and we get back what we said in the macro definition, nice!:

(let ((f (open "foo")))
  (format f "Hello, World!")
  (close f))

So yeah, you lose some, you gain some -- the ability to work in a higher abstraction level, closer to your problem (there's a reason most code today is not written in assembly language...)